It’s really not fair to do a direct currency conversion to determine what it costs to live in Australia as compared to your home country. It’s all relative to how much money you make, what type of accommodation you will be living in, what city/town you will live in etc.

Have a look at these resources to help you work out how much it will really cost you to live in Australia.
Probably the most useful single site to start off with:
http://www.finfacts.ie/costofliving.htm
http://www.finfacts.ie/qualityoflife.htm

New South Wales Department of State and Regional Development (Current Facts, figures and Surveys regarding costs and quality of living in NSW Australia):
http://www.business.nsw.gov.au/living.asp?cid=26

The Big Mac Index:
The Economist's Big Mac index seeks to make exchange-rate theory more digestible. It is arguably the world's most accurate financial indicator to be based on a fast-food item.
http://www.economist.com/markets/Bigmac/

For prospective students: The links below may assist you in estimating and understanding the cost of living in Australia:
http://www.uts.edu.au/about/sydney/cost.html
http://www.studentservices.uwa.edu.au/page/15848 http://www.issupport.qut.edu.au/student/costofliving/
http://www.services.unimelb.edu.au/housing/lifeinmelb/costs.html