I seem to be completely astounded by what you're considering. You've already got Science @ Melbourne, why would you go to India or drop your place all together to try your luck interstate? If there are so little people who take the pathway you're considering, shouldn't that ring alarm bells? $180,000 is a LOT of money, I probably don't even want to know why money "is not a problem" for you. One way or another you're going to have to work hard, no matter which option you end up taking, so I don't really see the benefits of studying anywhere else except for here, right at your doorstep at Melbourne.
I also seem to be under the impression you're not doing this by your own interest, but I could be wrong.
This ^.
I honestly this its dumb to decline Bsc and just sit at home and prepare for umat.
A dear friend of mine did 0 study and got 76 percentile .... then studied his ass off and got 30% and 70% respectively the next 2 years.
its difficult to say how you will go in umat.
Dont drop out/not start bsc.
its just wasting your time ( unless you plan to work etc and not just study for umat alone).
goodluck ...... make sure you want med for the RIGHT reasons.
Really consider it.....
then if you chose its the right path for you .. start studying now for GPA in bsc.
science is such a ridiculously broad and easy course .. your GPA should be 6.5 ... . no disrespect to those doing science .. its a fantastic idea before med .... but honestly ... its so simple compared to some other courses which involve students your also competing with.
it dosnt matter what course you do .. so take advantage of science and get a high GPA ...... and Do Gamsat . study now ... in 2-3 years you may get into med.