You seem to be projecting assumption here. The comment you replied to says she's written books they've seen in a book store.
Also, note that the average book sells very few copies. Even traditionally published books. Some books have higher production values that'd justify a lot of extra effort, but tends to be linked to name recognition for people with very established names. It's not at all a given that all that much money has gone into producing these books.
Also, note that the average book sells very few copies. Even traditionally published books. Some books have higher production values that'd justify a lot of extra effort, but tends to be linked to name recognition for people with very established names. It's not at all a given that all that much money has gone into producing these books.