Hi
If it's just a 2 year voice contract required, there is still a way that sellers could get one for resale. Not only that. Demand would be reasonably high. What demand? Depending if Apple / AT&T require you to be within the discount qualifying period in order to purchase an iPhone, there will be those looking to eBay, ... to grab an iPhone without the need of extending their current contract.
What a person could do, in theory, is purchase an iPhone either as a new customer or renewal -- policy unknown --, purchase another phone -- likely cheaper -- that is either locked to AT&T or unlocked, use that for themselves, and sell the iPhone -- hopefully for a reasonable / worthwhile profit.
Unfortunately, there are still some major pieces missing from the puzzle.