My UK (or European perhaps?) readers may be interested to know that Sainsburys eBookStore is selling Terry Pratchett books cheaper than Amazon.
If you don't know Terry Pratchett, you are really missing out. I'm currently re-reading most of his books for about the third time. (Oh, take no notice of the garish covers. Terry told me that the publisher says they sell, but I never cared for their super-saturated colors much.) (Another note: his first two books are amongst my least favorites. Neither the story nor the humor is as sharp as it became in the witches books or the Watch (city guards) books.)
Ooh, I just thought of a funny coinkidink: I first discovered Pratchett when I lived in Edinburgh in 2000-2001. And it was in Sainsburys supermarket of all places!
(Well to be exact (and to increase the brackets count (!) in this post), the very first one I read was his very first, years earlier, but like I said, the first two did not catch my interest and I still think they are weaker (along with other books featuring Rincewind the wizard).)