Villager Market:

Don't you hate it when you can't find that villager deal? When all of the villagers just have horrible, overpriced deals that you don't even want to see ever again? Well, now you can switch through villagers and find the deal you want easily! Just hit a button!

This market is wired to kill the villager in the stand by using lava and then spawn a new villager with a dispenser full of spawn eggs!