This week the T-Mobile iPhone 5 was revealed with a pricing structure closer to that of an automobile than what's been common amongst smartphones over the past several years. While you pay just $99.99 USD initially, you then move forward with $20 payments for 24 months. Then your costs for data, voice, and text are separate (but still integrated into one bill in the end). Here's the real breakdown, step by step.
The iPhone 5 will cost you different amounts depending on which carrier you buy it from - and depending on if you purchase it "off contract" or not. You also have what might appear to be three different kinds of purchases on your hands now:
1. On-contract (each of the top three mobile carriers in the USA with 2-year contracts)
2. Off-contract (paying one since price once in one lump sum with no contractual obligations)
With your T-Mobile purchase, you'll be paying $99.99 USD down for starters - that's half the price (essentially) of the $199 you'll pay if you're purchasing the device with a 2-year contract with any of the top three mobile carriers in the USA.
1. $199 with subsidy costs built-in to your data/voice/text plan (you can't see it, but it's there).
2. $649 (we'll stick to the 16GB version since T-Mobile is advertising that model as their hero with $99.99 down and so forth)
3. $579.99 ($99.99 down with $20 per month for 24 months)
So why would you want to purchase an off-contract iPhone 5 from Apple for $649 then have it working with T-Mobile data? You wouldn't. That's absurd. If you want to purchase an iPhone 5 to use with T-Mobile, you can do so cheaper by buying it from T-Mobile with their "Simple Choice Plan" structure (that's what the hardware pricing plan T-Mobile is pushing is called).
Purchase an iPhone 5 with any carrier using a 2-year contract and you'll be paying an amount of cash built-in to your monthly payment well past the time that T-Mobile would allow you to be finished. With T-Mobile, there's a clear separation between your monthly bill for the hardware (that you're paying off) and the mobile service. With every other carrier, you continue to pay for the hardware forever - or until you end your service.