At what level of output is each additional roll of film worth more to consumers than it costs to produce? [Image description: The graph shows the market for rolls of film. Vertical axis is price and horizontal axis is rolls of film/week. There is a linear upward-sloping supply curve and a downward-sloping demand curve. The two curves intersect at a price of about 1.07 and a quantity of 100 rolls of film/week.]