discus2,
There are lots of Americans working in Australia on 457 visas, how many of the 3000 Boeing employees in Australia do you think are on those visas ? Northrop Grumman, Lockheed, GE, PW, IBM ? The aerospace/defense industry is full of them, on wages way above the Australian average.
Across all industries, 457 visa holders earn 34% more than local staff on average. With an average annual base salary of $94,000, the average 457 visa holder sits comfortably above the 75th percentile of Australian full time salaries.
Please stick to the facts.