I've tried both Buyee and Jauce, and all the stuff I've bought from both got here fine. Buyee has a nicer format, but I think I remember the Jauce fees being slightly cheaper. Maybe. Haven't used Jauce for several years, used Buyee last about a year ago. I'm conversational in Japanese and generally okay, but when I'm feeling lazy on YJA, I just right-click and ask Chrome to google translate the page. It's better than it used to be, and usually gets close enough as far as auction site descriptions go.
Also, Rod from Tetsuya Garage can bid on auctions on your behalf! He's got me a couple things, always been happy.