I'm not a business. YAJ is just a hobby to me.
Almost everything I post that is rare, I find in the vast space that is YAJ. My experience there has been pretty good. I have personal bought and sold items on there for a handful of Zilvians. I first show them a picture or link to item and quote them a price shipped to there door. Beware most items can't be had for any less than Forum/eBay prices. There is a fine line. Sure you may pick up a $250 part for a hundred but most likely your shipping cost (reliable shipping) is going to fill the gap.
I have spent over $4000 on YAJ over the last 3 years. Half of that in shipping. My "customers" here on Zilvia will tell you I always update there status via PM/Email asap. I take pictures when I receive an item and send the pics to the buyer. It is intensely time consuming. I spend almost 3 hrs or more everyday on YAJ. Unless you dedicate a generous amount of time and know what to look for and can translate the very hard to read/understand Japanese you will probably get "upside down" quickly.
With my service, I can't bid on seats, dashes, bumpers, engines/trans, full cars, glass, body panels, heavy drivetrain, ect.
Two important links:
Yahoo!??????
Language Tools
PM Me for more info.
Happy Searching!