A heads up: borrowing a Kindle book from OverDrive is no longer working to get the Whispersync price at Audible. I saw someone post about this at Goodreads and tested it for myself. True, alas.
I know that we lost this function before and got it back; I can only hope it happens again, but....
Of course I'm regretting all those Whispersync deals that I meant to get but hadn't got around to.