I generally don't like the idea of trade-ins, as I've found that it's usually the better deal to sell the old phone on Swappa or ebay. Trade-in deals with a carrier almost always involve owing the carrier money on the old device, and shifting the debt to the new device (which means the consumer is, in effect, renting their phone). I would recommend paying the device off as fast as possible, saving up a little each payday for a new device, buying the new phone UNLOCKED from the manufacturer (not the carrier), and selling the old one to replenish the phone fund.