Enchantment doesn't consume right amount of levels

Enchanting an item doesn't consume the right amount of levels, instead consumes as many levels as Lapis lazulis are used. For example, a level 30 enchantment consumes 3 Lapis lazuli, but only 3 levels.

Tested this with diamond tools and armor, and enchantments which requiere 1,2 or 3 Lapis lazuli.