So I have 3 lines currently, two iPhone 6 64GBs 1 year into 2 year contracts, and a dumb phone out of contract on a 15GB plan. I was thinking of updating to a 64GB iPhone 6s using the upgrade from the dumb phone account since ATT allows using upgrades from other accounts. Since I am on a 15GB plan, I figured switching to Next and getting the 25 dollar line discount would have been worth it, but the math doesn't seem to add up. Am I missing something or is the above correct? It seems like because I have a dumb phone who contract is offset from my phone line, I can update every year and its still cheaper if I go the contract option because I can sell the phone after the year instead of having to trade it in when using Next 12. I also looked into paying off NEXT after 1 year, and selling the phone, but that was still more expense. Is that right?