OP might also might be talking about the regular UQ 4 year program seeing as they referenced Canadian dollars and not U.S. dollars.
@Florentine I don't think the education will drastically differ between them. It depends on what your goals are. If your goals are to stay in Australia and train see which states provide the most spots for interns. If your goal is to return to Canada or train in the U.S. UQ will certainly have more Canadians and Americans to commiserate with. Although even at UQ a majority of Canadian students will continue to train in Australia as it is very difficult to match back home for them.
I'm not sure whether the price premium is worth it for you. No one will be able to answer that for you with any certainty as we all enrolled in just 1 medical school and have no basis of comparison.