One of the rarest video games on Earth is up for auction on eBay. But you’re gonna need quite a stack of cash if you want to get in on the action.

A factory-sealed copy of the North American version of Stadium Events for the Nintendo Entertainment System is up for sale on eBay. Bidding has already surpassed $22,000, with more than seven days left in the auction. Seller Menaceone listed the game for $5,000, and it jumped up to $22,100 after just 10 bids. That already makes it one of the most valuable games to ever go up on eBay. This marks a growing interest in classic, collectible video games.

The listing for this particular copy of Stadium Events notes that it is near-mint condition. It also come in an archival case that should protect it from the elements in the future.

So, what is Stadium Events and why is it so valuable? This is one of the first games to work with the Family Fun Fitness pad that developer Bandai released in the 1980s. Players could get up and jump up and down on the pads big foot-activated buttons, but Nintendo quickly acquired the technology from Bandai and rebranded the mat as the Power Pad. To prevent consumer confusion, the publisher put out a recall on the North American version of Stadium Events. Game historians believe that only 200 copies of this game ever reached consumers. Today, collectors estimate that fewer than 20 copies of this game exist. That makes the NA version of Stadium Events the rarest licensed NES release.

This isn’t the first time the game has gone up for auction. In 2011, another eBay seller got $22,800 for their factory-sealed version.

While the North American version of Stadium Events is extraordinarily rare, the European release is less so. That game, which debuted in 1987 in Germany and Sweden, now fetches a price of around $200 or more, depending on the condition.