Medicine probably shouldn't be characterised as an easy way to achieve a high income, but it is certainly a reliable way. You can bank on breaking $100,000 by the time you have completed post-graduate training (~5 - 8 years after the medical degree) and $200,000 further down the track (much more is available, of course, for those willing to go rural or who succeed in breaking into the more exclusive specialties).
(Edit:
Salaries for staff specialists, who have completed post-graduate training, working in the NSW public health system)