Enchant planner
Pick the item and the books you have. The planner tries every order and shows the cheapest one - which item goes left, which book right, and what each step costs.
Item
Enchantments
Total levels
Total XP
Most expensive step
Left slot = the item you keep, right slot = what gets used up. Cost = the right side's enchantments × their weight + the prior-work penalty of both sides (doubles with every anvil use).