I am a fan of this idea as it would bring another aspect to the game. However, please keep the potions bound. It would require hard-work, but people won't put the hardwork into it if they can just buy off of someone else. Granted, it would be another way to profit in the game, but there's already plenty of ways to do that.
Also, when it comes to using items, maybe allow different "classifications" of items such as common, unique, legendary, etc. to help increase potions stats/levels/duration/etc, create different types of potions, or other things like that. We can then start incorporating the legendary events more regularly, which would essentially create a group of people who just farm legendary items/elite items/etc just like plant hunters now.