We're still not entirely convinced of the in-game utility of Nintendo's Amiibo figures, even if the near-field communication plastic statues will soon unlock classic game demos on the Wii U. Regardless, the market can't seem to get enough of the little guys. Case in point: a limited-edition gold Mario Amiibo that is already reselling for up to $100 on eBay, a huge markup for the $13 MSRP.

Preorders for the limited edition gold Mario, offered exclusively at Walmart in the US, sold out about 15 minutes after going up on the retailer's website yesterday, despite a reported limit of two Amiibos per household. If you missed that tiny window to buy one, don't worry, you can check out one of the 177 currently running auctions for the figurine on eBay. That includes one auction that has been bid up to $710 and another at $510, though the bidding history on those outlier prices makes us suspicious of their legitimacy.

What seems more legitimate is the five completed "Buy It Now" listings that have already sold for $100 on the site. Even the cheapest Gold Mario Amiibos on eBay are going for $45, a nearly 250 percent markup. The median of the 140 completed auctions as of this writing is right around a $70 price.

This is just the latest and most extreme example of the frenzy surrounding Amiibo figures since the first wave launched last November. Collectors have gathered together to determine which Amiibo are hardest to find, and some have camped out outside their local retailers to get their hands on the latest wave of new figures before anyone else. And then there's the sky-high prices paid for sealed "defect" Amiibo, like this $25,000 legless Peach or this $2,500 Samus with two arm cannons.

Nintendo is riding the Amiibo trend all the way to the bank, with reported sales of 5.7 million figurines in 2014, primarily in the US and Canada. Some have accused the company of holding back supply intentionally to increase collectible demand, but Nintendo says that recent labor strife at West Coast US ports have been at least partially responsible for the lack of supply.

Going forward, Nintendo says limited store space means "some Amiibo may become standard models while others may be replaced once they sell out"; only figures "indispensable to play a certain game" will be restocked regularly. Translation: buy that Amiibo today, because we may not restock it tomorrow!

Recent history shows Nintendo consistently underestimating fan demand for sought-after limited edition offerings, either intentionally or unintentionally. Nintendo reportedly offered only a few hundred Hyrule Warriors limited-edition boxes to fans lined up at the exclusive sales point at the New York City Nintendo World store in September, leading resale prices to shoot up hundreds of dollars. And some pre-orders for a limited edition gold Majora's Mask-branded New Nintendo 3DS were canceled en masse earlier this month as retailers failed to get as many shipments as they expected.

Nintendo was a toy company for decades before it started selling video games, so it's somewhat appropriate that Amiibo sales are helping to buoy the slowly recovering company. We'll be happy if the trend eventually leads to a Balloon Fighter Amiibo that can sit on our desks. That would be worth $100, easy.