After several rounds of infecting and curing I have two clerics that have the same two trades jump to a high cost from a low cost. The villagers have been cured 5 or 6 times before the jump. I have tried curing them several times after and the cost of the two trades always remain high and the same value. Before the jump the cost was around 3-5. These villagers originally spawned into the world as zombie villagers and were never part of a natural generated village. There are about 10 villagers in the trading hall and all of them started as zombie villagers. I recently cured one of the librarians and two of his trades jumped in price after being low. Tried infecting and curing again and the prices stayed high.