Villager Prices

Villagers and cured zombie villagers are increasing their prices without limits. Happens when you trade the same item often. E.g. iron with blacksmiths.

What I expected to happen was...:
cured zombie villagers maintain discounted prices. The more you trade with a villager the better the discount.

What actually happened was...:
Some cured villagers would increase the prices of the item traded with often. Sometimes raising prices as high four times original price and higher.

Steps to Reproduce:
1. Trade often with a villager. E.g. iron with blacksmith.
2. blacksmith will continue to increase iron price if traded with day after day.
3. ...