I have a 13 Halfling Warrior on the Mithaniel Marr server and a 13 Iksar Monk on the Xev server. Two or three days ago, while playing my Warrior, an oldtimer told me about Disciplines, which I knew nothing about. He took me to the PoK and showed me where to buy the Tome of Focused Will Discipline, which I bought for 6gp and change.
Today I logged on with my Monk and was eager to buy the Discipline. When I went to the PoK the vendor wanted 388pp and change!! What gives??