Minecraft wiki entry for Things_not_to_do, associated text: Curing villagers can make them reduce prices and make things cheaper. It is a good idea to cure a zombie villager when you have the resources. If the trades are expensive, cure them multiple times, like infecting them and curing them. Do not do this on Easy or Normal difficulty as the villager has a 100% or 50% chance respectively to die from a zombie attack instead of being converted.