For T-Mobile's JUMP program are you essentially buying a new phone every 6 months, or whenever you decide to upgrade phones per your twice yearly allotment? So if you start with a $600 phone you have $600 in payments owed over 24 months. After 8 months if you jumped to a $550 phone, does that mean your payments and obligation now changes to $550 in payments owed over the next 24 months? In other words, are you basically committing yourself to another 2 years of payments each upgrade if you only make the initial (and minimum) down payment required to upgrade? Thanks.