Sole traders: how sneakers became as collectable as art

Sale of Kanye West's 2008 Grammys pair for $1.8m heralded era of investment grade trainers

To most people they just look like a pair of trainers or sneakers, but for Gerome Sapp the Nike Air Yeezy 1 Prototypes represent a watershed moment in design and modern commerce. If you're a sneakerhead, you know that sneaker," says Sapp.

The art market is paying attention, too. The shoes, co-designed by Kanye West and worn by him to the Grammys in 2008, became the most expensive ever sold when Sapp's company Rares bought them for $1.8m (1.28m) at Sotheby's in a private sale in April.