Go for it 166....Flying in the US is less than 50% of the cost of Australia...far better access to airports and airspace....controllers that are friendly and helpful.....far more sensible regulation....etc etc....
Unfortunately you will be spoiled for life and will be extremely dissapointed with the expense and inane ATC attitude towards GA back in Australia...for example Perth will not allow VFR transit through their Class C airspace (which is bigger than some Eurpoean countries) except via a couple of strictly enforced routes which serve no purpose other than sight-seeing of the CBD....and even then you better have filed a written flight plan unless you want to told "Standby remain OCTA" for the next 15 minutes...In the US you can transit Class B (over airports with 10 times the jet traffic) with a simple radio request...no questions asked....