A fabrication company wants to increase capacity by adding a new machine. The firm is considering proposals from vendor A and vendor B. The fixed costs for machine A are $90,000 and for machine B, $75,000. The variable cost for A is $15.00 per unit and for B, $18.00. The revenue generated by the units processed on these machines is $21 per unit. If the estimated output is 50000 units, which machine should be purchased?