I have a literally mint iPhone 3GS 16GB black. It has one or two small scuffs (1-1.5mm) on the bottom of the chrome bezel but that's it.
It has had a screen protector on since day 1 and also a case from the first two minutes of owning it. (I got a new one for £139 under warranty when I smashed the screen of my old one) It is about 3-4 months old. Its warranty expires November I think.
I was looking to upgrade to the iPhone 4 and was wondering how much I could get for it. I was thinking £320. Is that too much? Also, where should I sell it (here? :p ) Thanks for your help!