T mobile user wants iphone 5, monthly price of two year contract?

I'm a tmobile user that really wants to get the iphone 5.Is there any way to get the iphone 5 and still use tmobile, or will i be forced to open a new contract no matter what if i want the iphone 5? I'm apart of a tmobile family plan and it is only $30-40 a month, and I heard that the 2 year contract is $100+ a month.

EBay?

As for now, there's no way to use the iphone 5 with tmobile
when you get an iphone, you have to activate it and to activate it, you need a sim card that is compatible with the iphone which would be a Verizon, AT&T or sprint sim card.

But later on, probably a month or two later, you can buy the iphone without a contract and can get it unlocked. But this is really expensive. I'm talking about 600+ dollars. But by doing this, you can use it with tmobile but it may not works as well compared to you using a tmobile smart phone.