Today the exchange rate is like 1 USD = 75 JPY so the 3990000JPY translates something like 53000USD. But don't worry, he won't sell it to anybody anyways. He just put it on the list for fun. You can visit the K-staff and see it and smell it though! He himself wouldn't even drive this one as it'd add more miles. Whenever he wanted to move this SVX more than couple blocks, he would put it on to the flatbed truck and move it..
Downside. You can never buy that lowest mi SVX S4 in the pic.
Upside. There are tons of other mint S4 like that that you can actually buy at the K-Staff.