At Best Buy you can Trade Up to an iPhone 5c with 2-year agreement. Here's how it works: You get a minimum $100 Best Buy gift card after you trade in your working iPhone 4 or 4S (in-store) and use it toward the purchase of an iPhone 5c. Note: The trade-in value may be affected by the condition of the phone. Also, Best Buy recommends that, to save time getting the new iPhone, you should set up your iCloud account and back up data before coming to the store. Sales tax is charged in most states.