From July 1st., 2017 the "Reciprocity Fee" will no longer be required for Australian Citizens to enter Argentina.
Reciprocity Fee: suspension from July 1st, 2017
(Disposición 3908-E/2017, Dirección Nacional de Migraciones)
For more information:
http://www.csidn.cancilleria.gov.ar/en
http://servicios.infoleg.gob.ar/…/275000-2…/276305/norma.htm