Discriminating customers

This is to show that, for example, merchants don't buy everything from you that you've collected on your travels. A weaponsmith is unlikely to buy clothes, an alchemist is unlikely to buy your scavenged collection of stabby things and even blacksmith might not much care for used weapons except for the metal he can use. Most modern stores don't buy from customers (pawnshops being the obvious exception, antiquarian bookshops also commonly buy from customers).