I've only seen this book on my server's AH once since BC released.  200G starting, 250G buyout.  Needless to say, the player I bought it from is on my ignore list and has a note.  They ever ask for water, I'll ask them to fork over 250G and not blink twice about it.  Even though doing research 300G is the average price on all servers, it's still insane considering how much mages are expected to have the best water and fork it over with no complaints.  Currently, I'll only hand over crystal water to people who ask, glacier water is for me and my closest friends.  I reccommend the same for any other mages who pay unreasonable prices on this tome.  IE, you might want to think twice before trying to make a killing on this tome, right now I'll let my group wipe before handing over the water this creates for free I'm so mad about how much I had to pay for it.