The English language level 6 (for 'expert' speakers) proficiency test can be done in Australia with any ATO approved for it. ATO's endorsements can be viewed on the CASA website (
Flight crew exams and licences - Approved Testing Officers ) to find a suitable ATO in your area. For 15 minutes of his/her time and a few autographs, this will cost you anywhere between nil and $40, depending on how well you know the person.