I've been wondering that myself. They're expecting an AWFUL lot of pocket money from gamers. And yeah, you're getting more adults with jobs, but still, If you're going to charge that much, then I can only buy for my favorite game. And you're not going to make yours my favorite game if you make me purchase so many books at so high a price. I mean, full color is nice, but if it puts you into a collector's item range...
I paid less than $50 for a coffee table book at 300 pages from National Geographic of Astronomical photos. There are no "supplements" or repeat business they can count on from that sale. So what justifies a book with more conventional page size being that price when they can count on my repeat business? Is there that much demand? I guess I could believe it with certain merchandise based books, like Stargate, Star Trek, whatever, where there are fans who buy it even if they don't roleplay, but still... How do they expect to build a mass market?