Fees and charges are reviewed on 1 July each year.
A number of Visa Application Charges (VACs) and other fees will increase on 1 July 2009 in accordance with recent decisions made by the Australian Government.
A number of other VAC and fees will increase in accordance with changes in the Consumer Price Index, or in the case of the second instalment of the visa application charge for the Contributory Parent visa category, by the Contributory Parent Visa Composite Index.
Source : http://www.immi.gov.au/allforms/990i/increase-fees-charges.htm