850
What did you pay the author of the books and papers published that you used as sources in your own work? Do you pay those authors each time someone buys or reads your work? At most you pay $0-$15 for a book anyway.
In regards to free advertising when your source material is used... if your material is a good source and someone asks say ChatGPT, shouldn't your work be mentioned if someone asks for a book or paper and you have written something useful for it? Assuming it doesn't hallucinate.