US v Aussie wages v cost of living

There are way too many variables in your question. Easiest for you is to do a search (Google) for cost of living comparison and one for wages/earnings. There are plenty of web sites that will provide you the info based on the type of job, experience, education, and city. Also, don't forget the currency exchange rate. Lastly, benifits vary widely by company and type of job and if it's government or private sector.