I still owe $500 on my 7+ with T-mobile, and I want to switch to AT&T along with my wife (her 6+ is paid off). My sister-in-law needs a new phone (also with T-mobile) & said she would pay the $500. What would be the best route to take? I know my wife and I could take advantage of the B1G1 with the switcher offer from AT&T so if I sold my sister-in-law my 7+, I couldn't take advantage of that. At the same time I am leaning towards a sim-free 8+ anyways. What do you guys think?