variable cost is $14.00 for A and $10.00 for B. The revenue generated by each unit is $22.00. Vendor A and Vendor B have the same cost when the output volume = units (round your response to the nearest whole number). variable cost is $14.00 for A and $10.00 for B. The revenue generated by each unit is $22.00. Vendor A and Vendor B have the same cost when the output volume = units (round your response to the nearest whole number)