As others have said, BN has an exclusive Bargain-priced ($19.95, I believe) leather-bound edition of Wicked/Son of a Witch, and Gregory Maguire's latest book "A Lion Among Men" is coming out within the next month. That coupled with the fact that it is close to Halloween, and it is the fifth anniversary of the Broadway Cast Recording makes it a no-brainer to promote Wicked merchandise and discount the price of the CD.
"[Gore] was widely perceived as arrogant. If you know something, you're not smart. You're a smarty-pants. It's annoying. People get annoyed with your knowledge. It goes back to high school, to not doing your homework ... 'There's something I should know, I don't know why I should know it but someone knows it and I don't. So I'm going to have to make fun of him now.'"
-Sarah Vowell, The Partly-Cloudy Patriot