So I decided to go from my dumb phone to an iphone but im still under contract.

I called att and a customer representative told me I had two options:

1.Pay $250 for an early upgrade(with another two year contract)+ the price of the iphone

2. Cancel this line and pay a etf of $122(I bought this phone in may 2011) then add a line and get the iphone on that.

So basically this method would cost me $128 less.

Am I allowed to do method 2 because some people told me I can't and if I can why would they think I'd choose early upgrade when canceling my current line and adding a new one would cost way less.

 By the way, I'm on a family plan with 3 lines currently