I would think a chance for existing items to break when taking/causing damage, or for them to have some things stolen if/when they lose certain quests. Otherwise they will soon run out of things they need to buy. Just more +x stuff so that they can have items to deal with things at the higher levels.
Are weapons/armour going to function in different ways at all? Depending on what they hit/are hit with? If so, there are a lot more weapons that could be added.
Shields, dagger (in case main weapon breaks or such)
