You have no concept of how much people are willing to pay for the new iPhone just after launch. You could easily sell for enough to cover the contract price of the iPhone and the full price of another.
And you don't know how to read. I never said that he couldn't sell an iphone and cover the upgrade cost plus the off contract cost of the skyrocket. What I said is that it's darn near impossible to do all that AND make $200 off the whole transaction.
Maybe you should re-read my original post... hopefully your reading comprehension will be better the second time 'round