An Item that can Reduce the Repair Cost of Tools

This would be a fairly rare item that could be used with a weapon or tool to lower its repair cost, either linearly or exponentially based on the current cost. It would be used either in an anvil or the smithing table, and it is found underground in chests.

An item like this could make it so that bows that have infinity can be repaired, but work still has to go into it. Every world I play I normally just put mending on my bow and carry around arrows, as that seems to be easier than making a bunch of new bows. Using an item that could change that though could make infinity more of a competitor to mending, and allow for more diversity in the choice of enchantments players use on their gear.

This item could also open the door to more enchantments that are incompatible with mending. This could allow more diversity in the enchantments that players choose to use on their gear. Currently it seems as though all players have relatively similar setups, making use of the same enchantments every time.

To get this item the player would have to find chests underground, whether that be in a dungeon or the underground mineshaft, but I think it should be in a way that encourages caving. As well, if a cave update for the game comes out sometime in the future, this item could be worthwhile loot that players would want to find. An important note though would be to NOT let Villagers sell this item, as it would defeat the purpose in a lot of ways, and would be far to easy for them to get a hold of.