Yes - imported cars are crazy in Australia, first there is import duty (suposed to protect local manufacturing) and then there is the taxes. On my new E92 M3 purchased in NSW I paid $36,000 in taxes!
New M3's will be from $155k-$190k depending on options and Sedan/Coupe/Conv.
As for real-estate we have some very good websites for this, try http://www.domain.com.au
as a start. Be warned if you are planning on renting the market is very hot right now and waiting lists for properties can be long - especially in the inner cities.