Books teach abilities and specializations rather than single crafts; many are tiny-supply world drops with some of the most erratic charts in the catalog.
Book (Recipe)
Auction-house prices and price history for Book in MoP Classic.
57 items in Recipes › Book are currently auctionable in Mists of Pandaria Classic.
Prices refresh daily from TradeSkillMaster (TSM), so day-to-day gaps in lower-volume listings are expected rather than a collection problem.
Book listings link to price-history pages with per-realm buyout, average, and median data for Mists of Pandaria Classic.