I would like to purchase an iPhone. The only problem is, I don't want to leave my T Mobile service. I talked to a T Mobile representative today, and they told me I can go to AT&T or Apple, and tell them I want to buy an iPhone to use for T Mobile, and they will unlock it. But if I have to pay an extra $100-$150, I would rather find a way to do it for free. Has anyone tried this before on their own and been successful?