My coworker Mr. Vetter found this. And it's only, from various links off elecom.co.jp, about 4500 Yen!
BUT!
they don't ship out of Japan: none of the links off elecom.co.jp do.
Anyone who has a suggestion on how I may get two of these mice (David wants the black one, I want the silver one, we both want the one that is Masamune-designed), please email me (and I imagine you know where to do so).
On the other hand IF ANYONE GIVES ME THIS I WILL HURT THEM.