When I first heard word of a new grey Nintendo World Championship cartridge being put up for auction on eBay, I didn't think much of it. True, the game is one of the rarest in existence, as it was given out only to 90 lucky winners of a nationwide contest in 1991. One only appears for sale publicly once every couple years or so. Other copies of the grey NWC cartridge have gone for over $10,000 at auction, placing it among the rarest and most valuable video games in existence.

Still, this version of the game is less collectible than the "holy grail" gold version (which was only given to 26 winners of a Nintendo Power contest), and the cart on offer is only in merely "acceptable" condition with a badly torn label. I figured that condition explained why the cartridge hadn't even seen a single bid at its $5,000 asking price when I first stumbled onto it earlier this week.

What a difference a few days makes. With about seven hours to go, the auction has now attracted over 300 bids and an current asking price of over $98,000. That obliterates the previous record price for the sale of a single video game, which was set when a seemingly one-of-a-kind Legend of Zelda prototype cart sold for $55,000 in 2012 (Update: a sealed-in-box copy of Stadium Events actually set the new record when it sold for $75,000 a few months ago).

The meteoric bid price increase for this auction is more than a a little bit suspect at this point, considering it's currently going for more than five times as much as the record $18,000 record price for a rarer, gold NWC cart sold privately in 2010 (one that was in much better condition, it should be noted). The bidding history shows the first bid didn't come in until yesterday morning, and the semi-anonymized bidder tracking shows only a dozen or so potential buyers being responsible for the majority of the price increase, most of whom only have moderate eBay histories in video game bidding.

Previous video game auctions have been outbid to absurd prices by suspected shill bidders, and there is some suspicion that it is happening again with this auction. It would take some coordination to get such price inflation among many different bidders, though, and all of those bids are considered binding contracts by eBay (unless they're retracted at the last minute as sometimes happens).

Others are questioning the authenticity of the game on offer; it wouldn't be that hard to stick a reproduction cartridge in a new casing and slap a fake, "torn" label on there. The seller, for his part, says he acquired the game in 2004 or 2005 from a collector going by the handle DreamTR, and traces its lineage before that to a collector in Norway.

While it's not impossible that this auction has just been the subject of a bidding frenzy after attracting wide-ranging media coverage earlier in the week, some caution is warranted until the auction actually ends and a sale is actually confirmed. Still, the seller doesn't seem too concerned about the suspiciously high price his auction is getting. "As high as this is going, my guess is the buyer and I will have to do an escrowed check or involve banks wiring money," the seller writes. "Not sure Paypal is a secure enough method of transfer."