Cool, I have the money etc. now and would love to actually go to melbourne uni for med.
If you're doing accounting you will need to do a fairly extensive course on the first year sciences to get through the gamsat as there's a decent amount of organic chem and physics that will go right over your head otherwise. The UMAT murders everyone, even the people I know that did really well say it was more or less a fluke; i.e. they were the ones that managed to correctly pick 1 out of 2 seemingly correct answers a higher percentage of the time then everyone else. I'm not too sure how the whole coming back from overseas works, but if you are going to be living in this country for your working years I'd seemingly suggest trying to get into med here.
No one is at the polar extreme of only doing med for the money / prestiege, but there are of course varying temperments that exist in the proffesion dependant on a number of factors. Bonded places for this reason are quite a good thing; take the prentenious little 24 year old princess and stick her in the emergency department of a rural town for 5 years till her sense of reality adjusts.