My wife and I were just at an Apple store last Friday to get her an iPhone 5 and we were offered either the 2 year committment or an outright purchase. We went with the 2 year committment, but the fact that we were offered an outright purchase with no contract means that that option is there.
However, I think you might have to wait a few weeks or so. When I got my own iPhone 5 I pre-ordered. Apple's website did NOT offer me a no contract purchase option then. So, it must have come later.
BTW, do yourself a favor and buy from Apple. Avoid buying from Sprint, either at a store or on their site. We bought direct from Apple both times. The reason for that is that you are only dealing with Apple. You don't have to worry about the damn Sprint CSRs trying to sell you crap, lying to you about this and that and everything else. You can get Applecare+ direct from Apple and only deal with Apple.
I have completely cut out Sprint this way. The only way they get involved is when activating the phone or paying my bill. I've already had my own iPhone 5 replaced once and Apple took care of it. No Assurion, no deductibles, no Sprint employees asking a million questions and giving you the feeling that YOU are trying to rip off Sprint and that YOU are lying and that your phone is just perfectly fine when it isn't.
Just my two cents.
