IMO drop rate of IT spellbooks is insane. I have also spent a week and leveled beyond 50 with no book drop. Current drop chance, according to l2wiki is 0,01 - 0,05%, comparable to full drop rate.
I understand classic has different ruleset than original L2, but what is the goal here? To waste a month of life chasing low lvl spellbok while at the same time hi lvl skills are much easier obtainable? It's easier to get 3rd prof skills than those, for God's sake!
I think i'm not the only one that recommends increase droprate of ~4x spellbooks.