Not sure if you are still in Japan or what part of Japan you are in but the best astro shop I have purchased from was in a part of Tokyo, the shop is called Seihosha, 1 minute from the Suidoubashi JR train station on the Soubu line.
I purchased my 10XW there for $270 after the currency conversion. I also saw some LVW's for around $180 AUD. I am going back in March and will buy a 17mm LVW and maybe an XW or two.
If you need directions to the shop, here is their web-site.
www.seihosha.co.jp
After much research, this shop is the cheapest I have found in Japan, and the best service.