OP on trade, fix any obvious mistakes:
Humans farm mainly for food, but also for tobacco or hemp. Very, very few humans actually use any of these, and elves find their herbs in the wilds, but dwarves may be interested in buying some. Maybe before sealing themselves up after a migration, or some scouts importing the stuff.
Dwarves produce metal and gems, but dont trade them often. Metal is used for tools and weapons, gems are used for toys and decoration.
Elves sell tons of leather, dry meat, herbs to humans in exchange for grain, ornaments, decoration, slaves.
They also exchange goods with humans and smaller forts by raiding them and taking what they can. They would consider the other races poor, as they dont own any herds.