(formerly MetroPCS) does not "buy" used cell phones for cash, but they do offer a trade-in program where you can receive credit toward the purchase of a new device or service. How the Trade-In Program Works
: When shopping for a new device, you can receive a trade-in estimate based on your old phone's model and condition.
: Certain Metro plans include "built-in upgrades," allowing customers who have been on an eligible plan for 12 months to trade in a working phone for the same deals offered to new customers.