The value of an item is in a perfect economy determined by the 
laws of supply and demand. The fewer there is of an item the higher the 
price will be, and vice versa. The higher the demand the higher the 
price will be, and vice versa. The highest value should thus be items 
that are low in supply and high in demand, and also vice versa.Hope this
 helps. Let me know if you need additional help!