So you want to cheap out by picking up a used system? Not a bad idea, systems depreciate fast, and the money you save can get you more games or accessories. However, you also don't want to sink money into a lemon, particularly if you're buying from a private party or a pawn shop who isn't going to offer any kind of warranty.
You need to keep two things in mind: Condition and price. As you examine the system, each problem you note should reduce the price accordingly. Start with a dollar figure in mind, usually about $10-20 less than what you'd buy the same system, used, from a leading retailer. At the moment, EB et al are offering the PS2 and Xbox for $149, and the Cube for $99.
I'll start with the PS2. First, flip the console over and count the square buttons that cover the screws. Current production models have eight, launch era PS2s will have 10. If it's a launch PS2, deduct $40.
Then, estimate the dust level. If he hasn't cleaned it off, this may indicate further neglect. Look for caked dust on the front intakes to the right of the USB ports, and on the vent fan at the rear. White powdery dust that blows off easily isn't a huge concern (it's actually mostly people dust: dead skin cells and hair particles) dense, sticky brown dirt indicates a life in a damp or humid environment. Deduct between $5 to $30 for dust.
Look for physical damage. Corners that are rounded off or dented in and scratches indicate how hard a life the unit has led so far. Also check to see if the controller ports are loose: this means the system has fallen onto its face before, hard enough to break the port mounts. Deduct $5-15, depending on how much this bothers you. If the face to the CD tray is loose or broken off, it's either suffered a fall or someone got a disc stuck in there and tried to pry it open. Deduct $10 for that. See if the AV cable fits snugly or if it's loose. This is the source of many annoying and intermittant PS2 problems. Knock another $10 off for a loose port. Look to see if the VOID sticker on the case near the power plug has been tampered with. Some people cut them with a sharp knife rather than peel it off. If it's been opened, the price is now $20. You're looking at either a problem system or one that's been modded. Either way, walk.
Now, plug it in. You'll need a DVD (silver bottom) and a CD game (blue bottom, or an original (non burned) music CD). With the system on and plugged into a TV, put the DVD game in the tray and close it using the button. When the tray is closed, hit reset. See how long it takes for the system to read the DVD game and start it. If the system goes from the initial animation directly to the 'Playstation 2' splash, deduct no money, that's how it should be. If it goes to the browser first, knock off $20, more if it takes more than 10 seconds of sitting at the browser. You're looking at an impending disc read error. Do the same with the CD game. If you hear a chattering noise like a slipping clutch on a BMW 2002, that's a weak spindle magnet. Easy to replace, or Sony will fix it for you, but you won't be able to play CD games until it's fixed. Deduct at least $20 for that, more if you have a bunch of blue bottom games.
Also don't forget to examine the cables and the controller cable for nicks or chewing. If they're damaged, deduct their replacement cost.
Now you've got a price. If the system is undamaged but has problems reading discs, you might want to lowball the guy and then send it to Sony for repairs. You're looking at about a 4-6 week wait, but it's a good way to get an as new PS2 for cheap. EB games will also give up to $50 trade in for a broken but complete (cables, 1 controller) PS2.
For the Xbox, follow the same general idea concerning dust and condition. You can roughly judge the age of the system by flipping it over and reading the build date on the bottom. Newer the better, obviously, but if an old system performs good, don't be afraid to buy it. An older build system may sit at the bottom of a pile while newer ones are piled on top and sold first, so the build date doesn't tell you how long it's been in service.
Take off extra money for observed drop damage (rounded or flattened corners, scrapes, etc), since the Xbox is so sensitive to that.
Use a DVD or Xbox game to test the system. As it powers up, listen for a loud clunk or pop from the hard drive. If it does, deduct $80. Put the disc in and see how long it takes to go from the dashboard to the X logo splashscreen. More than 15 seconds indicates a soon to expire DVD drive; deduct $70, or walk.
See if the warranty and warning labels on the bottom have been cut or heat gunned off (will show up as ripples in the plastic), like the PS2 the price is now $20 as it's either been modded or apart by someone other than Microsoft.
Again, inspect the cables and controller. If you prefer the S controller and it comes with the Duke, knock a few more bucks off. Hopefully you'll have a game like Halo on hand so you can test the full range of the analog sticks. They're usually pretty durable, but hard use, drops, or being stepped on can screw things up. If it comes with only a 3rd party controller, deduct $30 so you can get a real one.
Gamecube pricing is a funny thing. As of right now, you can pick up a new system with either a game or the Gameboy Player for $150, which seems to imply that the new price of a bare system is $100, but used systems are usually priced at $99. I would start a private seller at $50 or so, since that's about what they'd get on tradein at one of the major game stores.
Gamecubes seem to be fairly durable systems. If it's clean and free of dust, boots a disc rapidly from power off, isn't excessively loud, and doesn't have any external damage or frayed cables, go ahead and offer full price. But be sure to check the full range of movement on the controllers, the big N still hasn't learned how to make durable analog sticks.
Game Boys: Current used pricing on GBA SPs seems to be in the $85 area. Start there. Normal GBAs tend to go for $49-39, depending on the store, Color systems for about $29, Pockets for $19, and Originals for $12 or so.
Game Boys are usually very durable, with a few cosmetic weak spots. If there's something broken enough to notice, it's usually not fixable for less than the cost of a new unit. So if the system you're looking at has more than cosmetic problems, walk.
For a GBA, deduct $5 for a scratched screen, it's easy and cheap to replace the plastic cover, see http://pocket.ign.com/articles/097/097154p1.html for details. Shallow scuffs may be polished out with a soft cloth and some toothpaste (the old fashioned white kind, not a gel) since it's a mild abrasive.
Battery doors are available on Ebay for between $3-7, plus shipping. If the unit is missing its door, deduct that.
Kid grime is always a problem, but it can be quickly cleaned off with Windex and a paper towel. Use that as a bargaining angle.
Bring a game to test, preferably something that makes use of all the buttons, including shoulder buttons for SPs and GBAs. Inspect the inside of the battery compartment for signs of leaking batteries. Don't add any money for aftermarket rechargable battery packs. The quality of these is uniformly low, and most can't hold a charge longer than Radio Shack rechargables.
SPs: It is vitally important that you test the function of the charger and the battery. See if it will hold a significant charge. If the seller isn't willing to wait around while to see how long it'll take for the battery to run down, walk. Nintendo has had a huge (for Nintendo) return rate on bad batteries or flaky chargers. Either way, make sure you run the SP on the battery for at least an hour.
GBAs: If it has an Afterburner or other aftermarket backlight installed, walk unless the owner has a recipt showing professional installation. It's not easy to do, but a lot of people have attempted it. Test the shoulder buttons, they're the first to fail.
Color, Pocket and O: If it works, and looks ok, go for it. There really isn't a lot to go wrong.
Older systems: With EB offering warranteed N64s, PSXes and Dreamcasts for $20, it isn't worth the effort to grade one that has any problems. Either walk or lowball him if you need a parts system.
Super Nintendo systems seem to have regained collector interest recently. I'd consider an excellent condition system with 2 controllers a good deal at $30 or so. Be sure and see if the AC adaptor connector is in good shape, this can break off and is not easily replacable.
Front loading NES' have a limited lifespan. If the power light blinks when a cartridge is inserted, the cartridge teeth need to be replaced. The part costs about $10 or less in quantity, and the replacement can be done in about half an hour. Unless the seller can document this being done recently, don't pay more than $10 for an NES.
Good luck!
You need to keep two things in mind: Condition and price. As you examine the system, each problem you note should reduce the price accordingly. Start with a dollar figure in mind, usually about $10-20 less than what you'd buy the same system, used, from a leading retailer. At the moment, EB et al are offering the PS2 and Xbox for $149, and the Cube for $99.
I'll start with the PS2. First, flip the console over and count the square buttons that cover the screws. Current production models have eight, launch era PS2s will have 10. If it's a launch PS2, deduct $40.
Then, estimate the dust level. If he hasn't cleaned it off, this may indicate further neglect. Look for caked dust on the front intakes to the right of the USB ports, and on the vent fan at the rear. White powdery dust that blows off easily isn't a huge concern (it's actually mostly people dust: dead skin cells and hair particles) dense, sticky brown dirt indicates a life in a damp or humid environment. Deduct between $5 to $30 for dust.
Look for physical damage. Corners that are rounded off or dented in and scratches indicate how hard a life the unit has led so far. Also check to see if the controller ports are loose: this means the system has fallen onto its face before, hard enough to break the port mounts. Deduct $5-15, depending on how much this bothers you. If the face to the CD tray is loose or broken off, it's either suffered a fall or someone got a disc stuck in there and tried to pry it open. Deduct $10 for that. See if the AV cable fits snugly or if it's loose. This is the source of many annoying and intermittant PS2 problems. Knock another $10 off for a loose port. Look to see if the VOID sticker on the case near the power plug has been tampered with. Some people cut them with a sharp knife rather than peel it off. If it's been opened, the price is now $20. You're looking at either a problem system or one that's been modded. Either way, walk.
Now, plug it in. You'll need a DVD (silver bottom) and a CD game (blue bottom, or an original (non burned) music CD). With the system on and plugged into a TV, put the DVD game in the tray and close it using the button. When the tray is closed, hit reset. See how long it takes for the system to read the DVD game and start it. If the system goes from the initial animation directly to the 'Playstation 2' splash, deduct no money, that's how it should be. If it goes to the browser first, knock off $20, more if it takes more than 10 seconds of sitting at the browser. You're looking at an impending disc read error. Do the same with the CD game. If you hear a chattering noise like a slipping clutch on a BMW 2002, that's a weak spindle magnet. Easy to replace, or Sony will fix it for you, but you won't be able to play CD games until it's fixed. Deduct at least $20 for that, more if you have a bunch of blue bottom games.
Also don't forget to examine the cables and the controller cable for nicks or chewing. If they're damaged, deduct their replacement cost.
Now you've got a price. If the system is undamaged but has problems reading discs, you might want to lowball the guy and then send it to Sony for repairs. You're looking at about a 4-6 week wait, but it's a good way to get an as new PS2 for cheap. EB games will also give up to $50 trade in for a broken but complete (cables, 1 controller) PS2.
For the Xbox, follow the same general idea concerning dust and condition. You can roughly judge the age of the system by flipping it over and reading the build date on the bottom. Newer the better, obviously, but if an old system performs good, don't be afraid to buy it. An older build system may sit at the bottom of a pile while newer ones are piled on top and sold first, so the build date doesn't tell you how long it's been in service.
Take off extra money for observed drop damage (rounded or flattened corners, scrapes, etc), since the Xbox is so sensitive to that.
Use a DVD or Xbox game to test the system. As it powers up, listen for a loud clunk or pop from the hard drive. If it does, deduct $80. Put the disc in and see how long it takes to go from the dashboard to the X logo splashscreen. More than 15 seconds indicates a soon to expire DVD drive; deduct $70, or walk.
See if the warranty and warning labels on the bottom have been cut or heat gunned off (will show up as ripples in the plastic), like the PS2 the price is now $20 as it's either been modded or apart by someone other than Microsoft.
Again, inspect the cables and controller. If you prefer the S controller and it comes with the Duke, knock a few more bucks off. Hopefully you'll have a game like Halo on hand so you can test the full range of the analog sticks. They're usually pretty durable, but hard use, drops, or being stepped on can screw things up. If it comes with only a 3rd party controller, deduct $30 so you can get a real one.
Gamecube pricing is a funny thing. As of right now, you can pick up a new system with either a game or the Gameboy Player for $150, which seems to imply that the new price of a bare system is $100, but used systems are usually priced at $99. I would start a private seller at $50 or so, since that's about what they'd get on tradein at one of the major game stores.
Gamecubes seem to be fairly durable systems. If it's clean and free of dust, boots a disc rapidly from power off, isn't excessively loud, and doesn't have any external damage or frayed cables, go ahead and offer full price. But be sure to check the full range of movement on the controllers, the big N still hasn't learned how to make durable analog sticks.
Game Boys: Current used pricing on GBA SPs seems to be in the $85 area. Start there. Normal GBAs tend to go for $49-39, depending on the store, Color systems for about $29, Pockets for $19, and Originals for $12 or so.
Game Boys are usually very durable, with a few cosmetic weak spots. If there's something broken enough to notice, it's usually not fixable for less than the cost of a new unit. So if the system you're looking at has more than cosmetic problems, walk.
For a GBA, deduct $5 for a scratched screen, it's easy and cheap to replace the plastic cover, see http://pocket.ign.com/articles/097/097154p1.html for details. Shallow scuffs may be polished out with a soft cloth and some toothpaste (the old fashioned white kind, not a gel) since it's a mild abrasive.
Battery doors are available on Ebay for between $3-7, plus shipping. If the unit is missing its door, deduct that.
Kid grime is always a problem, but it can be quickly cleaned off with Windex and a paper towel. Use that as a bargaining angle.
Bring a game to test, preferably something that makes use of all the buttons, including shoulder buttons for SPs and GBAs. Inspect the inside of the battery compartment for signs of leaking batteries. Don't add any money for aftermarket rechargable battery packs. The quality of these is uniformly low, and most can't hold a charge longer than Radio Shack rechargables.
SPs: It is vitally important that you test the function of the charger and the battery. See if it will hold a significant charge. If the seller isn't willing to wait around while to see how long it'll take for the battery to run down, walk. Nintendo has had a huge (for Nintendo) return rate on bad batteries or flaky chargers. Either way, make sure you run the SP on the battery for at least an hour.
GBAs: If it has an Afterburner or other aftermarket backlight installed, walk unless the owner has a recipt showing professional installation. It's not easy to do, but a lot of people have attempted it. Test the shoulder buttons, they're the first to fail.
Color, Pocket and O: If it works, and looks ok, go for it. There really isn't a lot to go wrong.
Older systems: With EB offering warranteed N64s, PSXes and Dreamcasts for $20, it isn't worth the effort to grade one that has any problems. Either walk or lowball him if you need a parts system.
Super Nintendo systems seem to have regained collector interest recently. I'd consider an excellent condition system with 2 controllers a good deal at $30 or so. Be sure and see if the AC adaptor connector is in good shape, this can break off and is not easily replacable.
Front loading NES' have a limited lifespan. If the power light blinks when a cartridge is inserted, the cartridge teeth need to be replaced. The part costs about $10 or less in quantity, and the replacement can be done in about half an hour. Unless the seller can document this being done recently, don't pay more than $10 for an NES.
Good luck!