I too make six figures, and I don't think I do anything as expensive as completing flight school and co-owning a Cessna. I mean, my house is more expensive than that, I guess, and my car is (barely) more expensive than flight school might be, but surely amateur pilots have houses and cars too. About the only expense I have that might come close to serious flying as a hobby would be pets, but outside of the one time we had to pay for chemo for our dog it's not that expensive.