It's sad to hear him talk about such a small amount of money for his efforts. Sounds like the book wasn't worth his effort. Even artists understand the value of their work.
https://signalvnoise.com/archives2/picasso_paula_scher_and_t...
https://signalvnoise.com/archives2/picasso_paula_scher_and_t...
At a company I worked for previously, some people thought it would be nice to invite him for giving a talk. Even though there was a reasonable budget available, it still didn't go through because the guy is apparently pretty expensive.
It always struck me as strange that the person who typically makes the least out of a book is the author (unless you're a best seller)