Apple's base model iPhones have collectively accounted for 42% of its smartphone sales this year, but iPhone Pro Max devices ...

This larger cousin to the iPhone 6 bumps the screen size to 5.5 inches. Compared to the iPhone 5s it also improves the camera and processor, adds NFC, and switches to a thinner, more rounded design.

The iPhone has been around for 17 years, and in that time, its number of features and (seemingly) its price have also increased. But just how much has the price of the iPhone actually changed ...