 If market conditions are perfect competition, producers would charge a price of $0.10, and every customer whose marginal benefit exceeds $0.10 would buy a nail.A monopoly producer of this product would typically charge whatever price will yield the greatest profit for themselves, regardless of lost efficiency for the economy as a whole.In this example, the monopoly producer charges $0.60 per nail, thus excluding every customer from the market with a marginal benefit less than $0.60.