The desal plant is not a good example. There are very few projects like that about.
Government funded gravy train.
You are right about high wages when you quote figures as you have done.
However, you should also be looking at history, comparison and context.
We live in a country which has a very high if not the highest cost of living in the world. Our utilities (gas, electricity water, council rates and telephone/internet) are amongst the most expensive in the world. This drives up the costs of other things such as food and anything manufactured in Australia When you couple this with the high AU$, that drives up the cost of exports and drives down the price of imports.
Comparing wages in AU$ to wages in US$ is not a fair comparison. If you compared AU houses to US houses, you'd probably find Australian houses are ten times more expensive than US houses. A friend is in constant contact with people in the US. They constantly compare prices. A good example in vending machine drinks. I have been noting the cost of a can of Coke from vending machines in Victoria. They are usually around the $4 mark. In the US, 80c.
Another thing that should be considered is supply and demand. If there is short supply of skills and demand is high, that drives wages up. Once the wages are up and demand drops, people are retrenched.
This has happened to me. For the past five or six years I have been in a job that has been paying me about three times what my job overseas would pay. (Bear in mind I was working for a multinational company in the global market competing with US, Europe and Asia.) What kept us competitive was we worked so much smarter than overseas companies. When the AU$ went up, we ceased to represent value for money and available projects dried up.
The problem is too complex just to blame high wages and unions. You also have to blame government policy, the money changers (i.e. stock market and banks), and numerous other parties that have their snout in the trough.

