Sims 4 potions selling for $0

There's a few mods out there that can change it so that your potions actually have a monetary value; there's a bit of a trade-off however; namely some potions will now have a monetary value to make as well as to sell.

Try searching for the mods (Unfortunately mods can't be advertised in Answers HQ, so I can only suggest them). The last the one I was talking about was updated just after Realm of Magic was released; it also included making Herbalism objects on cauldrons for a monetary value (Similar to if you have ingredients for food. You can reduce or eliminate the price if you have the ingredients on hand.)

Note: Use mods at your own risk.

- B