Sotheby’s this week partnered with sneaker e-commerce giant Stadium Goods to hold a sneaker auction, with some pretty rare and very expensive shoes up for bid.

The auction house expected to fetch $160,000 on a pair of Nikes from the 70s designed by Nike co-founder Bill Bowerman and $18,000 for pair of limited-edition Nikes inspired by the movie “Back to the Future.”

In the end, all but one lot was snapped up by collector Miles Spencer Nadal. Nadal acquired 99 pairs for $850,000 in a private sale.

It’s part of an ongoing departure from traditional auctions that attract an older, conventional art collector, said Julia Halperin, executive editor with Artnet News.

“Young people with money are very interested in sneakers and Sotheby’s is very interested in young people with money,” she said.

According to market research company NPD Group, global demand for all sneakers is rising, which is fueling the collectibles market. Sports business analyst Matt Powell said shoe companies want a bigger piece of the action, and so they’re making more limited-edition kicks. 

“Where they might have made 500 pairs, once,” said Powell, “now, maybe, they’re making 5,000 pairs or 50,000 pairs.”