There seems to be an issue relative to cured zombie villager prices regarding Farmer villagers. This seems to affect pumpkin prices only. As you can see in the screenshot the original price is 6 emeralds but it goes up each time I trade a stack or so with him. See the timestamps of the screenshots. It started at 1 pumpkin for 1 emerald and gradually went up to 11 at the moment which far more than the regular farmer villager price.

The villager has been cured 3 minecraft nights ago, no villager has been harmed in the process (or after) and all other "cured villager" discounts seem to work as intended (be it melons or golden carrots remaining at 1:1) .