No because when you go to sign up they will see you use to be with them and you will be required to go back to your old phone and plan. If you pay the ETF, you have 90 days ( I think it is) to come back to everything, after that you will need to start over. Paying the ETF is not the way to go.
Upgrade you plan to the 900 min plan for 59.99 (20.00 more a month). Do an early upgrade when you are 1 year into the contract. Once you have the phone drop back to the 39.99 plan. You will have to keep the data plan.