The iPhone 6S officially becomes available for purchase on Friday, but if you haven't already preordered it, then you might be fishing around trying to find where you can get the best deal on it. Trying to analyze each mobile carrier's plan and the total cost of ownership for the iPhone 6S can be dizzying, and this year it's even more complicated because Apple Inc. (NASDAQ:AAPL) has added its own upgrade program. We've combined all the data in one place for you, however, thanks to WalletHub's Cell Phone Savings Calculator. Sprint offers the best deal on the iPhone 6S After plugging in the numbers, the firm reports that Sprint Corporation (NYSE:S)'s leasing plan is the cheapest option overall, for both individual mobile phone users and those with a... More