I have family that do outdoor karting, and they are learning just how expensive it gets. They are certainly not the 1%, and are actually considering switching their kid to spec miata as running a actual car is cheaper than karting. The kids they race against are sons (almost entirely sons) of ex f1 drivers, leading political figures of nations, and ultra wealthy. And this is all US based karting which has no segway into f1. It's truly a 1% sport, you either need to be ultra wealthy or very quickly get supported by someone with that level of wealth.