Gotta love all the Aussie threads each winter in the UK!

Various sites:

www.realestate.com.au
www.realestateview.com.au
www.domain.com.au

www.carsales.com.au - For cars but someone will post that question up next.

As a very general guide, Melbourne and Sydney are more business centers for a lot of multinationals however each city has a good size center. Swings and roundabouts for all but in general Sydney will be the most expensive like London, Pops would be best advised on answering that although he has posted up prices before.

As for living over here. The backpacker visa is available for 18-30 year olds for 1 year and extendable to 2 years after spending 3 months working in a farming type role (there are some work limitations on this visa). Alternatively a normal ETA visa (holiday one) is 3 months but doesnt allow you to work. If you have a trade you can apply to migrate which is what my brother did and is happilly here as a Carpenter.