Scenario 131 6 Barney builds custom wooden birdhouses. He can make 150 birdhouses per month and sell them for $50 each. His average total cost is $30 per birdhouse. 42. Refer to Scenario 13-16. Barney's monthly total revenue is a. $12,000. b. $7,500. 0. $4,500. (1. $1,500