Villager specialists

Specialist villagers are quite rare and can move from village to village and can sell items from potion making to the nether. Each specialist has a unique look to what they sell such as miners will have a mining helmet and overalls while specialist who sell potions would wear a brown robe with the hood up. Each village has a max of 3 and specialist cant breed with one another, their shop is tied with one sole location or set of items so specialist like a miner wouldn't sell items like endstone or swords, however these vilagers don't sell for cheap as items has a five through ten emerald cost with all items and items can be sold to them, not only that but sellling items is different with specialist and they would buy items that isn't in their specialization but it would only give 1 emerald and items for their specialization will give 3 emeralds