I dunno I'll dig around and see what I can find. Here you go man. http://www.ripoffreport.com/reports/0/350/RipOff0350907.htm
eBay could help. But with any 360 used or new, beware of the RROD and see if there are any kinds of warranties or guarantees.
i would be wherry(sp?) of used 360's...i'd make sure you have a valid warranty before you get one you never know when they are going to crap out