Suppose a cigar manufacturer currently sells 1,500 cigars per week and makes a profit of $3,000 per week. the plant foreman observes, "although the last 500 cigars we produced and sold increased our revenue by $7,500 and our costs by $7,000, we are only making an overall profit of $3,000 per week so i think we need to cut back on production. using marginal analysis terminology, what is another economic term for the incremental cost of producing the last 500 cigars?