Guide is a decent baseline but has some silly bits.
CPU and heatsink: Getting a non-k version is fine
if you don't want to overclock. If you do want to overclock, it's pointless. A k version is only, like, 10-15 dollars more, though (though the price difference increases when you buy an aftermarket fan, which is more-or-less necessary for overclocking but otherwise pointless). Not sure why they picked a 35
50 over a 3570, though, which again is a minor difference. I'd recommend either a 3570k with a heatsink (say, Coolermaster Hyper 212) to overclock or a regular 3570 for budget reasons.
Motherboard: The very basics of it are this: if you want to overclock, get a Z77 board. If you don't, get an H77. And don't overpay for features that you won't use.
RAM: "Hey guys, we're making a budget-ish computer build guide. How much extra unnecessary RAM should we throw in?"

you, Destructoid. Go with their second option. Most any 1.5v RAM will cost ~$40 at 8 gigs.
GPU: The 7770 is pretty weak compared to even their choice of processor. I don't know why the

they would tell you to spend $65 on RAM and you don't need and a heatsink you won't use then skimp on the god damn GPU. In addition to j-cart's recommendation, consider AMD's entry at that price level:
the 7850. Slightly better value:dollar, but AMD has a reputation for shitty driver issues. Choose as you will.
PSU: Seriously, j-cart? No. Use
this. You do not need 650w. I don't need 650w, and my computer draws a fair bit more power than anything you'll get for