After four decades of keeping his well-heeled clients in his iconic red-soled heels, shoe designer Christian Louboutin is now a billionaire. The 61-year-old designer is stepping into the billionaire ranks thanks to his eponymous fashion brand.

Christian Louboutin's trademark red-bottomed shoes have become iconic. Beyoncé wore a custom pair of boots for her Coachella performance, and Cardi B slipped on a pair of "bloody shoes" for her "Bodak Yellow" music video. But why do these heels cost hundr...