One of the great reasons the compilation is so incredibly rare is reportedly because, for an odd reason, Nintendo notably in North America and Australia had simply decided to discontinue printing any more copies merely a few months after it was first released. No official reasons were given for this, but it was likely due to the production cost of the custom-made metallic packaging the compilation disc was boxed in. It is not easy for a corners-cutting company like Nintendo to keep up. Some sites are even making a killing selling any unsold copies of the compilation at ridiculously high prices, which de-motivates people further at getting their hands on any of those left over or used copies.
As for myself, I was fortunate to actually find one of those rare copies in a little shop just a couple o' weeks ago! I managed to buy that copy before anyone else did! Apparently, nobody knew its real value, so I got it at the standard price of a Wii game too! Gosh, what are the chances for one to find a copy of the compilation in a shop over a year after it was discontinued!? So, yeah, anyway I'm basically saying I have a copy too, even though I have not played it much yet. If you're still interested in adding me anyway, send me a message with your Wii number, and I shall share mine in reply.