I couldn't resist getting the 2 books for $10 once shipping became free. So if anyone wants my picked over old book let me know since I don't need it now that I am getting 2 new and shiny ones again. At some point before the expire, I will be happy to pass off these 2 books, too. Probably around October 1.
I believe that you can go through any of the cash back sites to get this deal. I just clicked through the email I got from them before it was universally available. Too bad I was impatient. I am sure I will still get my money's worth in freebies.