Got this promotion from Sprint in an email. It may be YMMV. Went to check it out and the S21plus is only ~8 as well. Seems like a good deal if you are planning on sticking around Sprint/Tmobile anyhow and have one of the trade in devices.
Get the new Samsung Galaxy S21 5G for FREE
with eligible trade-in and 24 monthly bill credits. No new line req'd.
The new Galaxy S21 5G is here, and now T-Mobile customers can get our best offer available—$800 off with eligible trade-in. Capture incredible share-ready moments with the easy-to-use, multi-lens camera, all on the fastest Samsung processor ever.
Now that Sprint has joined T-Mobile, our network is even bigger and better. Unleash the full power of the Samsung Galaxy S21 5G on the 5G leader in coverage. Best of all—T-Mobile includes 5G data in your plan at no additional cost.
Tax on pre-credit price due at sale. Limited-time offer; subject to change. Qualifying credit, service, & trade-in (Samsung Galaxy S20 series, S20 FE, S10 series, S9 series, Note20 series, Note10 series, Note9 series; Apple iPhone 11 series, X series, XR series, XS series, XS Max; Google Pixel 4A, 4; OnePlus 8 5G, 8T+, 7T Pro; LG V60, Velvet, Wing) required. $10 SIM card, and, in stores & on customer service calls, $20 assisted or upgrade support charge may be required. If you cancel your line before receiving 24 bill credits, you may owe up to the full value of your device (e.g. $799.99 – Samsung Galaxy S21 5G 128GB); if canceling your account, you can contact us first to instead make discounted monthly balance payments. $800 via trade-in credit and bill credits; trade-in must be active, in good working condition and in good standing to receive credits; allow 2 bill cycles. Max 4/account. May not be combinable with some offers or discounts.