In the 1.15.0.55 beta, curing zombie villagers gives you discounts. However, curing a zombie villager and giving it a tool smith profession doesn't give discounts on the bell. Even after I cured the zombie villager, the bell is 30+ emeralds.

Steps to Reproduce:

1. Cure a zombie villager
2. Place a smithing table near the villager and wait for it to be claimed.
3. There are discounts on everything except the bell.