So I own an iPhone 6 64G, and on T-Mobile. I am looking to get a 7 (128g) or 7S (128g) I am torn which route to go. A)Sell the phone and get 100-150 for it, and buy full out. B) Do the apple upgrade program or C) Take the T-Mobile offer. I doubt Ill be switching carriers as my unlimited plan is much cheaper on T-Mobile than other carriers, but options A/B have that option. Any opinions?