Amazon itself doesn’t demand any expenses to self publish; instead they maintain a share with the income each book you sell. So your only fees are those related to modifying, formatting, and cover design to your book. Fortunately, you can unenroll your book following a duration of 90 days, so https://maplepublishers.com/blog/how-can-you-become-a-thriving-author-while-book-self-publishing-london/