Where is a reliable place to buy used iphones?

I need a new phone, but my contract is not up, so i'm planning on buying a used iphone. I know everyone says ebay or amazon, but who are trusted sellers on there? If you know of anywhere else please let me know, thanks.

Most GameStops buys/sells IPhones, IPods, ITouch(es), IPads and sell them for a reasonable price. Go there.

Used iphones
Source(s):
http://www.amazon.com/...lias%3Daps