Update: Pricing for the iPhone 8 was updated on September 12, 2018. Apple announced 3 new flagship models (iPhone Xs, iPhone Xs Max iPhone XR) and lowered the price of both the iPhone 8 and iPhone 7. The iPhone 6s and iPhone 6s Plus were discontinued.
Here is the pricing for the iPhone 8 and iPhone 8 Plus as of Sept. 12:
iPhone 8 (4.7-inch)