well with an iphone plan its a 2 year contract so when the new iphone comes out (if the policy is the same as last year) then if u want to upgrade it will coast a lot more for the phone. last year the phone was say 200$ then if u were sill in your contract it was like 600$. so with that we really dont know if they will change the policy
but if u log in on atts site they will tell u for sure