How much to charge to edit a book is a freelancer question. How much to edit a book is the author’s. Both fail if you do not name the level: developmental, copy/line, or proofread.
If you are the editor
Quote by level and word count, define rounds in writing, and do not call a proofread a developmental edit. Industry per-word bands move; your rate has to cover revisions you promised.
If you are the author
AuthorShelf’s listed editing: developmental $380, copyediting + proofreading $799 (confirm live product pages). A full freelancer stack plus cover plus interior often exceeds a self publishing package once you add project management time. Most debut authors who need production too start at Launch ($597) or Pro ($997).