Don't forget the USD prices we typically see for Japan-only watches include the costly shipment that the Japanese sellers must cover for international delivery to your door in a matter of days. It is an amazing operation -- they have to process the order, package the box well, ship very high priority, pay for the special delivery once in the US, with a delivery person specially running the package finally to you in the end. The cost of this shipping procedure is probably all rolled into the total price that we're seeing on the websites of Japanese sellers.
Worth every penny to me. (Especially in light of what has happened to Japan [March, 2011]... I don't mind sending money into the country.)
I just received the SBBN015 today. I'd say the price reflects the quality very fairly.
It is one solid watch and I'd buy it all over again. (In fact, I did. I had an SBBN017 but flipped it, missed it, so got this one.)