Went to my local Best Buy with my 360, power cable, controller (three things needed when I asked them) along with a few games.
I asked the Geek Squad staff member helping what was needed to trade-in the 360. She said the aforementioned items, not being bricked/RRODed, and that it has to have the seal.
My 360 didn't have a seal, so I was like "I'm
ed" but carried on. They rang up the games for me with their double trade value and then took off the faceplate. She looked for a second and went "Hmm, the seal's gone..."
I tried playing it off cool, which looking back was actually stupid as hell, but she went "well normally, I shouldn't allow non-sealed systems here, but I've seen other Best Buys doing so and Best Buy (meaning the company itself) really wants the 360s." She then checked the system number in the bottom (where the USBs would go, I think) and checked if the system worked. It actually had four red rings at first, but they connected it to a TV and saw that it works flawlessly.
I asked why Best Buy wanted the older systems and they said because of the motherboards and the general electronics and minerals in the systems. She said that it's hard to mine and constantly get the materials needed for newer electronics and that's the reason they were taking old systems - "to scrap them."
Satisfied, I took my $142 GC and tried the DualShock 4. Surprisingly, that was my biggest disappointment of the day