If you haven't started med yet, then maybe just defer your possible Monash offer, take a gap year and try for UWS next year - it would either get you into the cheaper uni without starting or give you time to save up a bit of money if you don't get in to UWS.
I am pretty sure that all Unis have a list of who gets an offer in a Med school elsewhere, and although they don't advertise it, they say its important for them to know this info prior to offering you a place (if any). SO its possible that they may not offer you a place if they know you already have accepted an offer at another Uni.
I actually know a few (more than 3) people all of whom transferred in different years from Bond to govt unis...... what do you all think might have happened there? As far as I know, none had any genuine hardship reasons, but then I don't know what excuse they actually gave the deans. I know them personally and know that there was no family reason. Maybe a personal health based reason might be acceptable? Something along the lines of.... I am allergic to this Uni...
