For some crazy & unknown reason, the first two in this trilogy had more than one print run, whilst this one only got one. Hopefully Del Rey will see sense & reprint it soon, but I've been waiting for a good 2 years now (no way am I paying £40 for a second-hand copy) so I wouldn't hold your breath!
I paid seventy-odd pounds for this book last month and just finished it tonight (I,ve been delaying finishing it because after this, there is no more for now...hopes I...) It was worth every penny. I laughed, cried - a lot in fact, gasped in realisation at things and I will now watch episodes and the movies with a little extra background in my head like being able to put a face to a name.
Try Play.com, sellers on Amazon charging too much for second-hand 'acceptable' copies. I just ordered last of Psi-Corp trilogy from PlayTrade seller TheBookDepository new for £7.49 thats instead of £7.99 being the cheapest alternative on Amazon and that was marked as 'Used-Acceptable' and a worn 'reading-copy'. Also if you want to wait a bit they do seem to have a seller in the states willing to sell the books to UK buyers very reasonably. The current situation with Amazon reminds me when I finished collecting the vids some idiot was trying to sell the last vid of season 5 (Objects at Rest/Sleeping in Light) for £50!