Few people buy these sort of books to read them. The way these things usually work is wealthy donors buy these books in bulk. Because they’re buying something, not donating to the campaign, it doesn’t go against donation caps. Also, unlike political campaign contributions, there’s also no restriction on who can buy a book, so it’s a way for foreigners to get money to a candidate. Either MTG has gotten a lot of money she shouldn’t have, and doesn’t want to disclose it, or she doesn’t have many rich friends left, and doesn’t want to embarrass herself.
Not to mention that it’s basically through a self-publsiher for the RNC. (Winning team publishing was founded after Trump got rejected by the big publishers on account of fact checking issues in his memoir.)
So she probably paid to have it published and actually lost money on it.
Don't forget, when the rich donors buy these cretins' books, they propel them to the bestseller list without a legitimate copy ever having to be sold or read.
Rep. Marjorie Taylor Greene (R-GA) has not disclosed profits she made on her latest book — and that could be because she's the book has sold few copies.