A big part of T-Mobile's UnCarrier plan revolves around the iPhone 5, and it turns out that T-Mo's offering the Apple flagship at a previously unheard-of price: $579. As CEO John Legere announced today, his company will be offering its AWS-equipped version of the iPhone 5 for $99, plus 24 monthly payments of $20. That's contract-free, but the device is locked until it's fully paid for, and the cheapest monthly plan to go with it is $50 for 500MB of data and unlimited voice and texting