I don't know if you know this but it is cheaper right now to buy an iphone and add it to a family line then it is to buy it any other way.
Buy iphone 4s for 150$, get 100$ amex rebate making total 50$ on contract. Then downgrade that line to voice only for $10 which will make the cost $230 for 23 months + $50 = $280.
Then you can join many others in bankrupting sprint on their foolish iphone deal
If adding a family line is not an option, check out cowboom.com they sell preowned stuff. And if it is not to your liking you can return it within 30 days for a full refund. Cowboom is owned by Best Buy.