@madmole Perhaps for later tier quests (5, or even 4) the trader could have a low chance of rewarding you with a piece of hazmat gear, or some pills to assist you surviving in the radiation in the wasteland? Or a recipe to craft a special pill(s) designed specifically for this purpose?
Edit: Another two higher tier quest item suggestions: "food packs" or "medical packs". These would contain a random assortment of food or medical supplies (respectictively). For instance, in a medical pack, you might rewarded you with two first aid bandages, two painkillers, one herbal antibiotics, and three Fortbites, for example. A "food pack" might reward you with one meat stew, one hobo stew, two chili dogs, and some dog food, for example. The loot tables of these "packs" could also be redistributed for lower tier quests.