First, let me point out that this is the US-spec phone on Japanese Amazon. Of course the US -spec phone is going to cost more in Japan. I'd assume there's probably a 50%+ markup. So this would actually be $850. Then, this is the most expensive version. Usually there's a 16, 32, and 64gb version of the iPhone with a $100 gap between each. So, $750 for the 32, and $650 for the 16.
This is the current chart for the iPhone 5ses without a SIM card.

Either that's a huge coincidence, or I was dead loving on.