Buying used equipment in Japan

hi I am using YahooAuction (almost like ebay, but much safer).
Yes, you need to know japanese to use it. Most of items on Yahoo is not really a good deal but sometimes you might find some good deals, especially if you looking for items that are not so popular here. There is quite a few used equipment dealers - but again, need japanese. This is the most popular used dealer - they operate quite a few shops and take trade ins: http://www.audiounion.jp/index.html
also, be aware that yen is very high comparing to dollar/euro so pricing is quite high, recently i buy my equipment in US (McIntosh can be very easy converted to 100 vac as long as it is a product other than current line, after you can probably sell it here with a good profit.
As far as speakers - JBL is very popular here and they have quite a lot different models than in US (older line).

http://category.auctions.yahoo.co.jp/list/%E6%9C%AC%E4%BD%93-%E7%9C%9F%E7%A9%BA%E7%AE%A1%E3%82%A2%E3%83%B3%E3%83%97-%E3%82%A2%E3%83%B3%E3%83%97-%E3%82%AA%E3%83%BC%E3%83%87%E3%82%A3%E3%82%AA%E6%A9%9F%E5%99%A8-%E5%AE%B6%E9%9B%BB-AV-%E3%82%AB%E3%83%A1%E3%83%A9/2084046925/?p=%E6%9C%AC%E4%BD%93&tab_ex=commerce&s1=cbids&o1=d&slider=0&b=1
this is a link to YahooAuction for used tube amplifiers - japanese, but it has pictures/names, so it should give you idea about the market here (im not into tubes so i dont have knowledge about pricing/brand names...)

C1ferrari, dont know of any agents here in japan, but if you are looking for something particular - let me know, maybe i can help you.

c1ferrari,
i sent email to you,
Regards,
Stan