To putt into perspective, a contract WITHOUT a phone for the same minutes and texts will cost ALOT less, you pay that much BECAUSE of the phone.
In the uk we get our iPhones unlocked and sim free. The 3GS was £549 for the 32gb that is $827 , before all of you started listing your phones so low a preowned one would sell for about $700.
I mean seriously, in the uk they even pay you £285 ($485) to RECYCLE the phone and you are selling them for ALOT LESS then that even.
If you do not believe me then see for yourself
https://moneysupermarket.money4mymobile.com/sell/mobile/apple-iphone-32gb-3g-s
Double what you are selling your phones for to RECYCLE it...