Most of the time, smartphone trade-in programs at retailers like Best Buy or carriers like Sprint are major ripoffs. You can usually get double, triple, or even more if you take the time to sell your phone on eBay instead, but T-Mobile – yet again – is seeking to change this practice and make it better for consumers.
In the spirit of all things Uncarrier, T-Mobile says that it plans to begin rigorously tracking the market and adjusting its trade-in prices every day to ensure it stays ahead of the other big carriers: Verizon, AT&T, and Sprint. To show that it’s serious, if you can find a carrier that will offer you a higher trade-in credit for your used phone than what T-Mobile quotes you, T-Mobile will pay you the difference, and give you a $50 bonus credit when signing up.
To make this even better, the offer is also good retroactively: this means that if you find a better deal within seven days of trading your phone in, you can still get the credit and the bonus. The balance will be applied to your bill within two or three months.
The promotion doesn’t start until September 17, and T-Mobile says it is running for “a limited time.” T-Mobile often makes its “limited time” promotions permanent, but since there’s no guarantee about this, you might want to do this soon after September 17 if you plan on trading a phone in eventually. To qualify, you also have to buy a new device from T-Mobile and either sign up for new service or continue your existing service.[T-Mobile]