That's all great, but reselling phones you legitimately buy on contract isn't scalping. And you only make that much money if you want to keep the contracts. If you have to cancel them, subtract the cancellation fees and that's not even close to $600/hr any more. I've pulled that game myself a few times (not for an iPhone though) when I've needed a new contract or a renewal. That's a nice quick buck, but it's not scalping.
I think you're being wildly optimistic to think your margin on a $300 iPad is going to be 63%. The margin on an iPhone 5, even selling at $1100, is 55%, and only because it's a high-end device. The scalping margin people will tolerate goes down with the retail price, not up. (exceptions for the large number of idiots in the world, of course...)
No sweat if it doesn't sell (which looks like it wont not as ebay is flooded with them) I'll take it back and not lose a dime. Maybe I'll keep it and give it as a present... who knows. As far as the semantics of what is and isn't scalping don't care what it's called. I bought a phone for X, sold if for Y and I come out on top by several hundred. No matter what you call it I think that's pretty cool.