The cost of a item differs from day to day, place to place and trader to trader. It is also dependent on your Personality ability. Below is however lists of prices in the game. Let your own level of common sense guide you from there. If you are a smith or other form of craftsman and are selling items then the creation cost of the item is half its price. This cost covers material and so on. You can also acquire the material by searching them out yourself, for example collecting herbs or buying a mine. Again, let your own level of common sense guide you from there.
List of common Weapons and their cost can be found
here.List of common Armor and their cost can be found
here.List of common Clothing and their cost can be found
here.List of common Ingredients and their cost can be found
here.List of common Potions and their cost can be found
here.List of common Scrolls and their cost can be found
here.List of common Miscellaneous Items and their cost can be found
here.
