I attached a screenshot of what tomsem is talking about. When I hover over the audible narration thingy it says that. I have bought a audio before, months ago from a book that was in KU, but did not have the audio as part of the borrow.
But when I look now under the ones I have checked out right now, I don't get this option, so I guess it depends on the book.
The example is also an amazon publisher book, but they don't seem to have the audio as part. But when I click on one I have currently checkout with KU and its also a amazon published, I don't get that hover thing at all. That is why I have been so confused at this thing and I wasn't able to help booklover on it.
Like this, I have this checked out with KU right now and like the Thomas and Mercer booklover posted, this is published by an amazon arm, Montlake. But when I look at that popup it tells me since I own both the ebook and the audio, I can switch between the two. Well I don't own either the ebook or the audio, I just have them checked out with KU. So there I do not get any option to buy the book for really any price right now as the audio is currently in my account as a borrow.
http://www.amazon.com/gp/product/B00...=dp_ku_cen_mbb
I attached the example of the popup of the book booklover posted for the popup.