Hey folks!  Apparently I’m a big silly potato and when I set up my listing for the 2-book pack I’m offering at the moment,  I didn’t look at the stock amounts when I made the listing, and it’s appeared as sold out for WEEKS.  It’s fixed now, the books are purchasable, and any domestic orders that come in between now and Tuesday (Dec 22) will get an automatic upgrade to Priority Mail so it can arrive in time for Christmas!  (International orders have to be sent the usual way, unfortunately, and it’s unlikely to arrive before the 25th.  Sorry about that.)