I do bet that less then 1% see any use as a Mahjong controller with most staying in boxes unloved in some collectors hidey hole, I would love to pick one up for about $50 and use it on the AES and Neo CD Mahjong games I have (basically all that are released), if I do not have any luck then a Neo Geo CD pad will die so I can wire a Mahjong panel to it.
i saw one the last couple of days on yahoo japan auctions, didn't know what it was till i had a look at it. it was boxed and good condition but don't think it was new. i'm sure the price was up to nearly 25 000 yen the last time i saw it. tried to find it but must have finished in the last 24 hours or so. couldn't work out a way to search ended listings like on ebay!