First, there is the Bazaar. Go to it for any of your item, treasure card, reagent, snack, and housing item needs. Also, there is the man next to Eudora Tangletree in Olde Town. Although, the Bazaar does have more reagents.
Yes, I get most of my reagents from the bazzar, but there is also a reagent vendor next to all recipie vendors, but they do not sell much, unfortunatley.
