I put the free link in the OP - probably after you guys first read it.
Even so I am finding others that are free that are not in that list. Also some are $.99 and then only $1.99 for the audiobook, so lots of good deals. Some of the free books we have posted have the audiobook for only a couple of dollars.
It does tell you if you already have the ebook, but if it is a book that you got for free but now has a price, you won't be able to get the audiobook without paying for the ebook.