Released in 1987 as a limited run, Stadium Events for the Nintendo Entertainment System was pulled from shelves in 1988 so Nintendo could rerelease the "family fun fitness" mat technology and game under new branding.
It's estimated that only 2,000 of the North American version were ever produced and of those only 200 hit stores before being recalled, according to retro gaming site Racketboy. Some believe only 20 now exist. Of those, two are factory sealed. And one of those two just went up for sale on eBay.
The game, which has been rated by VGGrader.Com as near mint, went on sale on eBay on Monday for $5,000. It has since had 15 bids from a dozen people, bumping the price, as of the writing of this story, up to $35,100.
The bidding ends on Thursday, Jan. 15 at 10 p.m. ET.
The person who listed the game writes that he has had the copy since the early 90s and that he used to work at Nintendo.
We've reached out to the lister for more details and will update this story when they respond.