Appraise Value of Item
A DC 20 Appraise check determines the value of a common item. If you succeed by 5 or more, you also determine if the item has magic properties, although this success does not grant knowledge of the magic item’s abilities. If you fail the check by less than 5, you determine the price of that item to within 20% of its actual value. If you fail this check by 5 or more, the price is wildly inaccurate, subject to GM discretion. Particularly rare or exotic items might increase the DC of this check by 5 or more.
wow, why is this skill so hard for low-level characters 
20