A shop wishes to raise its capacity by adding a new machine. The company is planning proposals from vendors A and B. The fixed costs for machine A are $90,000 and for machine B, $75,000. The variable cost for A is $15 per unit and for B $18 per unit. The revenue generated by the units processed on these machines is $22 unit. If the estimated output is 9,000 units which machine should be purchased?