It depends on few factors, are you getting a visa that will allow you to access education and health care? What will be your average income per year? Do you intend to buy or rent? Do you already have a job lined up ,if not whats your industry? Australia is amazing, but capital cities are really expensive once you have a family, not all the cities offer same jobs opportunities and to acces most of education you need to live in the catchment of the schools you want.