Making an audio book from a published book

I'm looking for a service or app that will take a book in text form and make an audiobook of it. I know there are some quality voice generators now days. I'm just looking for one that is legit and not too expensive. I reread a large number of books I loved from years ago but many aren't in audio format. More are getting converted all the time but I'd use a good app for some others if it had good feedback.