How do I bypass the to expensive error in the minecraft anvil? [duplicate]

There may not be a way to bypass the "Too Expensive!" warning, but you can work around it by anviling with a cheaper method. Using this method, it is theoretically possible to apply up to 30 enchantments to something.

The method works like this: Lets say you have a Sharpness V, Looting III, Sweeping Edge III, Mending, Unbreaking III, and Knockback II book.

Let's call these books with only 1 enchantment Book1. Next, combine a Book1 with another Book1 to get a Book2. Book2 should have 2 enchants on them. Repeat these steps:

Book1 + Book1 = Book2

Book2 + Book2 = Book3

Book3 + Book3 = Book4

etc

If this is unclear, this video does a great job explaining.

If you drop your item on the ground and run the command: /data merge entity @e[type=item,distance=..3,limit=1,sort=nearest] {Item:{tag:{RepairCost:0}}}, when you pick up the item, it should have the repair cost reset.