Alchemy books are free since you can win them in instances and by fighting guarnards at Relic Island. I sold 50 of my book fours, and am keeping 20 for myself just in case I get into the habit of compounding again. If I want some of the v6 items I might trade some IM stuff for it, but the money I'm saving on this game will go to potential pills for now, and maybe some weights to train my new wind knight and sharks.