I've put this in the forum because stock is hit and miss depending on what you are after, also there is only limited amounts.
At the Redcliffe, QLD store they have K&N air filters starting at $20 for a turbo diesel Land Cruiser.
I grabbed one for my Ford territory for $34.
Awesome price. Your local store may have lots or none (to quote Rivers).
Supposed to end 02/03/14.
http://www.supercheapauto.com.au/
Good luck.
Nice find. :-)