the limited-edition, Back to the Future-inspired Nike Mag must-have shoes quickly climbed above $3,500 in the first night of bidding, with some models topping $4,000.

But the shoes are not self-tying, a promotional video confirmed.

Nike unveiled the Air Mag at an event in Los Angeles on Thursday, after a teaser sent shoe aficionados and geeks drooling. Only 1,500 pairs of the Nike Mag will be released, 150 per night for the next ten nights, making them the latest must-have geek item. Who cares about the iPhone 5?

The shoes themselves are being sold on Nikemag.ebay.com, with proceeds going directly to the Michael J. Fox Foundation for Parkinson's Research, the foundation set up by the actor who played Marty McFly in the original Future trilogy. Sergey Brin, co-founder of Google, and his wife Anne Wojcicki, co-founder of personal genetics company 23andMe, are matching up to $50 million in funds raised by the Foundation between now and December 31, 2012.

Although the price for each pair of Nike Mags was originally set at 99 cents, buyers quickly pushed up the bids to above $2,000 per pair in just over 20 minutes. The shoes are available in men's sizes, from 7 to 13. Expedited shipping is free, and the auction is only open for U.S. residents.

eBay's rules allow shoppers to purchase up to 10 pairs. New auctions start at 8:30 PM PT each night.

"You are looking at the rarest of Nike Footwear," the item's description reads. "For 22 years they have existed only in the year 2015 on Marty McFly's feet. Today they are finally a reality.

"Famed Nike designer Tinker Hatfield and footwear innovator Tiffany Beers have returned to recreate the footwear legend," the description adds. "Based on an original movie prop used in Back to the Future Part II, the 2011 Nike MAG shoes have been entirely