So I have 3 lines on my plan, all upgrade eligible but only buying one iphone 5. I have a 4S, which somehow is not under contract even though I paid the upgrade price last year, so I was going to pass that off to my girlfriend when I get my new phone and sell her 3GS to gazelle or someone like that. Anyhow, I was wondering. The 4S is now $99 for a 16GB version. Does anyone know, since I don't need the new 4S, if I could buy it from ATT for $99 and sell it straight to Gazelle? If I could I reckon I would make back over $100 based on the selling price today for a 16GB iphone 4S.