Course fees vary between universities, schools, English language and vocation colleges in Western Australia. The different costs are calculated depending on the length and style of teaching required, resources used and qualification attained.
A rough guide to the course costs of different types of institution can be found at http://www.studyinaustralia.gov.au/en/Study-Costs/Fees. This website also covers important information about fee refunds.
If you are unsure about the amount required for any given course, contact the provider directly with your inquiries. Most institutions will have enrolment / admissions staff that can help you with your questions.
It is important that you know precisely what your course will cost before you make other commitments such as purchasing flights or finding accommodation. You will be required to pay your course costs before the commencement of your studies.
It is also important to note that not every study cost will be covered by course fees. Items such as text books and optional laboratory equipment may incur further costs.
Student services and amenities fees are currently compulsory for all students in universities and will need to be paid separately. You should have some money put aside to cover these incidental costs on top of the payment of your course fees. For more information about this issue contact the enrolment / admissions staff at your institution.