The bubble in Melbourne is rapidly deflating due to over-supply of units while Sydney is not as exposed the stalled growth of income means affordability is in crises. As a result offshore investors need to be relied to maintain the heat in the market – is that sustainable.
Meanwhile in Perth when allowing for inflation house prices are lower now than they were 10 years ago and most of the other capitals are not much better. Of course many mining dependent towns are in serious decline with values crashing.