well, it was on offer at some place i visited once in Brisbane years ago. it was pretty rare to find it and yes it was expensive but yes it was worth it.

the most important thing about it is the breed of cattle and how they raise it, and how they cure it after slaughter. probably a lot of common types of cattle would produce decent stuff if you treated them the same way. i'm pretty sure they let them run until more than 18 months also. not sure exactly what the procedures are but i don't think the cattle are especially different except for having been raised by meticulous japenese for a few hundred years. maybe longer, but i doubt that it's anything more than typical japanese excellence.