I took advantage of their trade in deal last friday and couldn't be happier. The new 360 is awesome looking and the extra hard drive space is nice as well. I got over $200 in trade for my system, wifi adapter, and memory card. I don't feel I got ripped off in the least bit when you consider a brand new elite with 2 games is $250. Quite the contrary, I think Gamestop was paying to much for the equipment...and obviously alot of gamers felt the same way.
You have to pick and choose when you trade games and systems in at Gamestop. The only time I trade games into them is when they give the 40-50 percent trade bonus on games. Combine that with the edge card and you get pretty good value on your games. Plus it's much easier than trying to Ebay your stuff.
