>>18269270
Kant and Hegel earned very little from their books. Hell, the Phenomenology of Spirit was printed in 1000 copies, Hegel would get 4% and they sold out in 1830 (one year before his death).
These people's earning came for either patrons (as in the case of Nietzsche for example) or from their lectures (as it was the case for Kant and Hegel).
Today thr situation is even more dire. You'll usually get less than 3% on a book sale, and the average philosophy book sell less thsn 150 copies (a philosophy book with 1000 sold copies is considered a best seller).
So, no, philosophers don't even make a living with their books, let alonr be rich. In fsct once you consider thr amount of working hours spent on it, it immediatly becomes clear that writing books is a financial net negative for philosophers.