themad
100+ Head-Fier
Not sure what kind of cables and stuff you are looking for, but the biggest ones are Yodobashi and Bic Camera. Apparently you can even contact them in English now (which is a big suprise for Japanese sites).I've a good friend coming from Japan in a few weeks. What are the reliable online audio shops in Japan? not necessarally stax dealer (apologies for the thread borrowing) as Im more inclined on getting cables and other small items, but surely will look into the prices of Staxes as well
If your friend is Japanese or local resident and can buy in person, it is usually cheaper than when they sell to foreigners.
I have also used Buyee.jp and Yahoo Auctions successfully.
Smaller and better (more variety, better prices) hi-fi shops are usually not easy to reach by email.