With all the items you find, selling them to the store is not the best way to make money. Store only buy items back at less that what it is originally cost. Some items are only worth 10-15% and the maximum is up to 50% of what it cost. Weapons and Armors can only be bought if you have enough money, and if you have the correct level to use the weapon itself (Items will show up in red if you are not able to use them).

World of Warcraft Shopkeepers

World of Warcraft NPCs (non player characters) have their name and the type of shop they run above their heads.