A signed set of the UK first editions of all 12 of my "Saga of Darren Shan" books sold for £320 in a recent ebay auction!! That's the highest price I've seen any of my books generate yet! Although no individual UK edition of any of my books is probably ever going to be hugely valuable (because they all had relatively large first print runs, even "Cirque Du Freak", unlike, say, the first "Harry Potter" or "His Dark Materials" books), a full set of first editions will, I think, be pretty hard (and expensive!) to track down in years to come. And a set of signed first editions will be even rarer!!! I've seen the number of first editions on sale on ebay drop considerably over the last couple of years, meaning they're harder to find and usually more costly when one comes along. Hold onto those first editions, little Shansters -- they could be worth money one day soon!!!!