Australia charges AU$20 for an electronic travel authority applicable to theses countries:
Brunei
Canada
Hong Kong SAR
Japan
Malaysia
Singapore
South Korea
United States of America
However electronic visa applications from these countries are free:
Andorra
Austria
Belgium
Bulgaria
Cyprus
Czech Republic
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Iceland
Ireland
Italy
Latvia
Liechtenstein
Lithuania
Luxembourg
Malta
Monaco
The Netherlands
Norway
Poland
Portugal
Romania
Republic of San Marino
Slovak Republic
Slovenia
Spain
Sweden
Switzerland
United Kingdom - British Citizen
Vatican City