What I ended up doing is buying Mass Effect 2 used at one Gamestop this afternoon, and driving five minutes to the other one to trade it in (making a nice ~34 cents after tax. XD) That way, I have a receipt to Gamestop that'll let me "return" the one I got from Gamestop's website (which I got for $41.xx) for $54.xx- netting a $13 profit. Sweet. :3
Thats if you get the game with in 7 days. Not a bad plan though.