Can't put every enchantment on a sword in survival mode

Abstract

It's impossible to put every sword enchantment on a sword in survival mode, since the last enchantment would cost 65 levels (which is "Too Expensive!").

Problem steps

• In creative mode, give yourself:
  a Diamond Sword,
  a Sharpness V book,
  a Sweeping Edge III book,
  a Looting III book,
  an Unbreaking III book,
  a Knockback II book,
  a Fire Aspect II book,
  and a Mending book.

• Apply them to the sword, one by one, in that order.

Expected behavior

Each enchantment cost less than 40 levels.

Observed behavior

The last enchantment (Mending) cost 65 levels, rendering it impossible to put all of these enchants on a Diamond Sword in Survival mode.