Many factors effect price such as The supply and demand of the product,scarcity of the product. Variable costs are costs that go up and down based on the supply and demand and the quantity of the items . Perfect competition is when there are businesses trying to sell similar products and the market is well informed on the prices. Monopolistic competition has businesses that sell very different products for the same problem. Also called The Competitive Market. Oligopoly is when the market is dominated by small businesses that sell similar goods and have influence over the price of the item. A Monopoly is when there is only one business that sells the product and can sell for any price that they desire with nearly no competition.