Sammy's Spray Paints is the world's sole producer of glow-in-the-dark spray paint. If Sammy's Spray Paints charges $18.50 for a can of glow-in-the-dark spray paint: Sammy should charge more than $18.50 per can of glow-in-the-dark spray paint because he clearly has monopoly power in the market. Sammy would certainly not make a profit if he charged less than $18.50 per can of glow-in-the-dark spray paint. the marginal cost of producing glow-in-the-dark spray paint is equal to $18.50. the marginal cost of producing glow-in-the-dark spray paint is less than $18.50