Getting a nice looking and user friendly site up and running is not very hard.
RE.com.au is quite a basic site with basic features and not a good one either. It also looks pretty outdated and doesn't use the latest technologies. They just have most of the traffic. That is agents listing...
Here are 4 that are under $500. One of them is $200. There are many more.
http://realestateyourway.com.au/sell-house-private-real-estate/no-agent-property/Listing-prices-and-packages
http://nomorecommission.com.au/
http://realprivate.com.au/
http://www.propertynow.com.au/
Cheers...