AT&T wireless is just like comcast. Discount if you cancel.
Needed to upgrade two iphone 4's. One to a Galaxy Note 2, the other to an iphone 5. Called and they wanted $649 for the galaxy, $499 for the iphone since both of those lines still have 7 months wait before they are eligible.
I told them I would just cancel the CSR said "ok, I'll transfer you"
The guy ends up upgrading the Galaxy note 2 for $224, and the iphone 5 for $246.
Just a fun fact..
I never thought of doing that with AT&T.