Start of balancing for the mod. Trader now might offers essence and Master and Exper tiers only and i removes somes ot the trades offer that where a little to op. Heart of the sea is still a buyable item, beacause it's not a renewable one otherwise and won't be faire on lage servers.
I've started to tweak some recipe for essences, but keep in minf that the goal IS to make them diifcult. Or more precisly, to force to progress to mid-to-late game to be able to craft them.
I sadly cannot remove them totaly from librarian trade, as i fell it would make them useless. But again, librarian are one of the major problem of Minecraft enchanting mechanics.