Complete Guide: iPhone 6S Price List in USA: ATT, Verizon, T-Mobile, Sprint. iPhone 6S Release Date -25th September. iPhone 6S Pre-Orders date – 12-th September. It’s awesome, and everyone wants one iPhone 6S with new features and specifications. But what’s it going to set you back? What is the price of the iPhone 6S and what’s the cost of the new AT&T, Verizon, T_Mobile or Sprint data plans? How much is it to upgrade from an existing iPhone6? Can you buy iPhone 6S without a contract? You know that iPhone 6S will be availability on September, and now you’ll know how much it’s actually going to cost to get in your hands. This is the complete iPhone 6S pricing guide.