 // Sky Marshals in Australia Their cost-effectiveness is being debated: They've cost the taxpayer $106 million so far, they travel in business class, and over the past four years Australia's armed air marshals have had to act only once — subduing a 68-year-old man who produced a small knife on a flight from Sydney to Cairns in 2003. I have not seen any similar cost analysis from the United States. Tags: air marshals, air travel, Australia, cost-benefit analysis, terrorism