I currently have an S21 Ultra, and am on a One plan.

It appears if I want to get a new S22 Ultra, T-mobile will charge me full retail and give me $385 trade in value on the old phone.

On the Samsung site (which is impacted ATM and is not doing a good job of completing orders), Samsung gives $50 off for activating on T-mobile, $800 trade-in value, and a $150 instant rebate for a net price of $350. You also get a $200 Samsung credit to use on accessories (can buy with order or use later), plus an additional $50 credit if you "reserved" with Samsung before today (it was a promotion where you registered and then would get the $50 additional credit.)

I haven't looked at other scenarios but I am paying $815 less by going directly to Samsung and getting an additional $250 credit that I wouldn't get if I bought from T-mobile.

Oh, one more thing - getting 10% cashback through topcashback.com, I've read that Rakuten is giving back 12%.

Edit: It appears that if I bought from T-mobile in addition to the $385 trade-in value mentioned above I would get an additional $115 value to bring it up to the $500 promotional trade-in value. So my net savings would be $115 less than I computed above.