you forgot Xfinity Mobile, $250 visa prepaid card with a samsung purchase if you order between Feb 26 and March 22 2018, with each phone up to 5 , $30 for S9 a month, or 719.99, $35 for S9+ a month, or 839.99, and up to $200 for trade-in...
Be advised, AT&T is only honoring the trade-in IF you're changing in from another carrier. They've refused to give credit for an S7 Edge trade-in because I'm an existing customer.