I don't have too much experience with AYCE in Japan, but I'm 1 for 1.

Gyu-Kaku in Osaka was, AYCE grilled meat, and it was all high quality meat, $17 CAD. Pure awesome. Much better than the Gyu-Kaku in Vancouver.
Also the AYCD (all-you-can-drink) for $12 in many izakaya's,

Japan.