How the number of buff slots is raised from 20 to 24: the four different books for levels 52, 61 and 76, where each of them comes from, and at which NPC the slots are learnt.
As you all surely know, in the C5 chronicle the number of buff slots was raised from 20 to 24. But so that life would not seem all honey, NCsoft introduced books with which this number is raised.
There are four books in all, one for each slot; all the books are different, and each kind adds one slot at levels 52, 61, 76 and 76. They are all learnt like ordinary skills: to learn, you put into the inventory the book needed for the buff slot and go to the NPC from whom you learn all the other skills. SP is not spent on expanding buff slots; only the book is needed. If you play on a server where all skills except the buff slot expansion are learnt automatically, then of course you do not know where skills are learnt. The general rule is this: crafters learn skills in the smithy, spoilers in the warehouse, fighters in the fighters' guild, mages in the magic guild, buffers in temples, dark elves in the dark elf guild, orcs in the orc guild.
Ancient Book - Divine Inspiration (Modern Language Version) is needed for learning the 21st buff slot after level 52; it is bought from the Black Marketeer of Mammon in any town (in Giran, for example, he stands in the corridor next to the auction manager, the corridor where we run to apply dyes). Earlier the book cost 600k in ancient adena; now on many servers ancient adena has for some reason been replaced with ordinary adena.
Ancient Book - Divine Inspiration (Original Language Version) is needed for learning the 22nd buff slot after level 61; it drops from raid bosses of levels 60-70+. These books are constantly in short supply for everybody, and so they have the highest price on the market.
Ancient Book - Divine Inspiration (Manuscript) is needed for learning the 23rd buff slot after level 76; it drops from epic raid bosses: Baium, Valakas and Scarlet van Halisha. Often they are simply handed out after a successful raid on an epic.
Ancient Book - Divine Inspiration (Original Version) is needed for learning the 24th buff slot after level 76; it drops from nobody and can be got only in exchange for Noblesse Gate Passes (the points for taking part in the Grand Olympiad). The book cannot be handed over or sold, so there is no point in talking about its price.