It all depends on how much time/money was spent. If it's a cheap product that was rushed, sure, there are going to be more errors. I always expect to find at least one or two in any book I read, if I'm honest, and it doesn't bother me too much, but any more would get annoying.

There has only ever been one book that I returned because the formatting and general polish was just unacceptable; a kindle version of one of Terry Pratchett's books, of all titles, and I think they did a complete recall at the time.