Contract or no?
Hombre07 said:
Upgrades can only be done on two years
Let me rephrase, upgrades can only be done on two years.
If you're worried about the phones not lasting 2 years, there's something called an exception upgrade. After 6 months of service you can get 1 year pricing on the phone if you renew your contract, which only ends up adding 6 months on to the existing contract.