Amazon's standard price for Kindle-formatted ebooks is pretty reasonable at $9.99, and a lot of titles are even available for less. But then we've got the the Kindle's equivalent of the Apple's "I Am Rich" app: the breathtakingly expensive Nuclear Energies, available for a mere $6,232. Wait, what? Nuclear Energies is a three-volume compendium of technical essays on energy. It is 602 pages long, but since the Kindle edition of James Joyce's Ulysses, clocking in at 816 pages, costs less than a buck, that's not much of an excuse. Hell, even Ron Paul's manifesto is only $9.99, and there's no way Nuclear Energies is more entertaining than that. But at least you're not getting completely ripped off: list price is $7,790, so it's sort of a bargain! [KindleBoards]
This book is never going to be in the same sales league as Harry Potter and the author is entitled to charge a fair price for his work- this book isn't something that's taken him a few rainy weekends to write in his spare time. The more specialised a subject and smaller the niche- the higher the cost.
Though Stephen Hawkin's managed to sell his Brief History Of Time to a mass audience- and that wasn't exactly light reading. One of the few books that made me think I really should have paid more attention in school!