Answer:
Demand and supply
Explanation:
In a market, the demand for a product and the supply of the products affect the price of them.
If a product has limited supply, the price will rise because it is rarer.
If a product has a lot of supply, the price will decrease because it is common.
If product demand is high, prices will rise because sellers want to earn more money.
If product demand is low, prices will sink because sellers need to make some sort of revenue and if the product doesn't sell, they've lost money. If they sell it at a lower price, at least they make some money back.
Of course, there are more factors but demand and supply are the main two, especially in a free market economy.
