I buy Audible credits, which come out to ~10/book. I don't see an option for them on the non-logged in page, but I buy a set of them, and then can use them how

I buy Audible credits, which come out to ~10/book. I don't see an option for them on the non-logged in page, but I buy a set of them, and then can use them how I want, not per month. While the Netflix model is nice for residual content, 90% of the books I want are available on Audible - I'd rather have that selection than a more limited selection I could get in a subscription model. I think some places do a subscription, though - Have you looked at Playster?