(Need help ASAP)
Five factors that caused the fall of the Roman Empire include:

dishonesty
violence
decrease in trade
natural disasters
decrease in value of money
war between countries
collapse of road system
overworked soil and poor crop harvest

To relate to humans in a relational humanly way. 

If a particular resource is not useful or needed then the price would be considerably low. once that resource is needed the price or value will raise depending on how useful or needed it is especially if the resource is low in quantity, the consumers would pay whatever they have to, to get that material.