I can't buy from your link due to location, if I go search for it myself, its 9.99.
though you are right, no paperbacks show, hardcovers do though.
You said you are in the UK, which is probably showing you different results due to different publishers.
I blame you if amazon starts trying to sell me Scalzi
if I wanted to read Dick or Heinlein, I would read them, not some guy who rewrote the cliff notes.