Hmmm, I just looked it up at Amazon, where I bought my copy. Their price is $28 with free shipping.
The book is a technical read for sure, not for the beginner. I'd call it a very worthwhile book for the user who has a lot of experience/practice with the program under his belt and who is intellectually curious. The author is very detail oriented and there is much to be learned from the book. The tools contained on the CD are very useful and expand the capability of PSE.
My 2 cents worth.