If you're upgrading, what do you do with your old iPhone?
There are various websites that allow you to cash in on your smart phone.
Gazelle is one, where a 16GB iPhone 4S in good condition sells for $280.
Buy My Tronics is offering $253 for the same phone.
You can also use a trade-in program like Amazon, which quoted a $314 gift card for the 4S and Apple is offering $285 in credit.