And why are these shoes now so expensive? Doc Martens are a style icon ... from a family-owned local factory to an international fashion brand owned by a private-equity firm.

However, this also makes them more expensive than many of the best running shoes, so they're less suited ... up our favorites across a range of brands and styles.

These shoes were both sold in limited releases, so why did Jordans become so much more expensive? It all has to do with the value of the Jordan brand and how it makes and markets its iconic sneakers.