Varied fetch quests. Lower tier version is to collect easily accessible items like paper/scrap poly and turn in a stack of ~20 to trader, higher tier would be more specific: turning in a level 4 magnum modded a certain way. This makes fetch quests more engaging and adds material scarcity in the player inventory.
Also adding trader improvements, if a trader starts out with a broken forge for example the player can turn in a working forge to the trader to replace it. This could get a reward, or it could allow the trader to sell more building materials associated with those crafting stations.