How much cash will Game Stop give for a pristine Xbox 360 Elite?

I bought an Elite 360 about three months ago, but I never use it and I'm ready to sell it. It came w/ Kung Fu Panda and Lego Indy Jones. I have everything including packaging. I paid $420 for it with taxes. I am willing to let it go for $220 but no less than that. Anyone interested? Anyone know or work at Game Stop that could tell me cuz they ( GS ) wouldnt tell me w/o bringing it in and I know the scam...they think I'll sell it just because I took the time to bring it in but I figure someone MUST know. Thanks!