It can vary quite a bit - and it may be worthwhile to remember that the majority of Australian universities have moved from the MBBS to the MD qualification, which is a different kettle of fish entirely.
That said, I know that James Cook University in northern Queensland offers the MBBS on its Townsville campus. Its website quotes fees for international students (which the wording of the question implies you would be) as $53,000 per year. Note, however, the following:
That’s based on the fees for students starting in 2018. The fees will be higher for anyone starting in 2019 (or indeed in 2020, as the deadline to apply for 2019 has already passed).
The fees typically increase every year by a couple of percent.
JCU’s MBBS program is 6 years in duration. Assuming that you’d be charged $53,000 per year for those six years (which is wrong, as discussed above), you’d be paying $318,000 over the course of the degree, and that’s on top of living expenses and anything else. Not cheap at all.
Medical degrees of any sort are seriously competitive to get into in Australia. You know that one kid at your school who seemed to get the best marks everywhere? He’s not guaranteed admission to an MBBS or an MD anywhere in the country.
Harry Kriewaldt, Historian in training (PhD candidate), inveterate traveller