http://dicksmith.com.au/product/xs1878web/
Norton Internet Security 2011 for 3 Users + Online back-up
Found on the site, I currently have this installed, and it's a great anti-virus and cheap.
This product is normally found around $70-80. On sale today only and online exclusive.
You can buy the 2012 version (OEM - 3 user pack) for $33 from ARC Computers (delivery charge applies)
http://www.arc.com.au/pub.php?gid=23245&pid=42074&p=product