I'm buying the iPhone 6 64 GB T-Mobile Contract Free?

I want to know if its unlocked (Factory Unlocked). And if I can use any carriers like Simple Mobile ( Which is my carrier NOW!)

*If not unlocked, how much will it cost to unlock it*

Better off buying a contract free iphone from the apple store either online or in person as they are factory unlocked will work with any sim based company

Call of several Unlocking services near you (Google or use Craigslist to find them), and ask what it will cost.

After you find out, you have two options, get the carrier (T-Mobile) to unlock the phone for free, or pay a unlocking service to charge you what it costs to unlock the phone.

Can you use the UNLOCKED phone, on a different GSM cell phone carrier, YES, as long as the phone has not been reported Lost, Stolen or is being currently financed. IF any IMEI service shows that the phone is being financed or reported lost or stolen, the phone will be ineligible to be activated on that service. The only way to avoid this is to buy the phone at full retail price the day you bring it home.