This was a surprise to us since Amazon has not ordered any copies of this edition and I was wondering how that was possible. When I clicked on the link they provided to order the 50th Anniversary edition what Amazon does is divert the request away from the 50th Anniversary edition to an earlier, different edition. What is worse, is that the 50th Anniversary edition is sold through our shop on Amazon. We find this highly deceptive, if not dishonest. People searching for a particular edition of the book are being diverted away from that edition by Amazon.
We have emailed Amazon regarding this deceptive practice (which actually is illegal) and await a response from them but we won't hold our breath. Getting meaningful replies from Amazon is like the transparency policy at the Kremlin.