Games Lore Ltd., who operate as an affiliate on Amazon UK,
appear to have Discworld available for a reasonable price.
I just hope that some of the vendors have it in, by whatever route, at UK Games Expo next month. I'm running two demo games there, and I've done an interview about it for Tabletop Gaming magazine, which should be out at the con. If Esdevium have a stand and have contrived to make me look like an idiot, I may need some self-control not to say something to them.