I think the point here is that individuals with necessary experience have a higher economic efficiency. The obvious choice is to hire one 18 dollar an hour tes

I think the point here is that individuals with necessary experience have a higher economic efficiency. The obvious choice is to hire one 18 dollar an hour tester and 4 9 dollar an hour testers. After a training period (probably < a month), you'll have 2 quitters and 3 good testers at 2/3rds the price.