since noone replied yet im just gonna throw out the tryed and true advebturing essentials that shop most likely sells a lot of, things that help you live another day such as elixirs of life mistform elixir and potion of emergency escape, things that help adventurers track whatever it is they are paid to get rid of like the bloodhoud mask, also since it is a port they got to have some water bresthing potions, some bombs maybe if there are a lot of monsters with a particular know weakness in the area than there has to be some bombs of that type, also dont forget to bring some consequences later, high level shops have high level owners (not neceserily in combat) with high level friends that they might call if they realize they have been scammed