I have bad news for all the people that are planning to mass produce emeralds, there is a limit on how many times you can trade your villager.
There is a limit on how many times you can trade with
A villager. That's why you get 2 of them and breed them yourself. Voila! You can now trade as much as you want.
You just have to kill off the villagers who won't trade anymore, so new ones will breed.
