Airlinedream I reckon you are looking at something like this:
50 hours in a 172 for a PPL @ average $280.00 = $14,000.00 Now you have an Aussie PPL
Another 70 hours in command towards a CPL in a cheapie, say $220.00 would be around $15,400.00 Now you are ready to begin CPL training.
Another 30 hours in say a 182 at around $400.00 is another $12,000.00
Budget so far is $41,400.00
Add medical, exam fees, text books, accommodation etc and the budget will soon blow way past $50K and there is a huge proviso, the above hours are for a dedicated and talented student, an average punter will need more hours. It also assumes you can find an instructor who you like and a flying school who can put the package together. Good luck here although the instructor/school combo certainly exists.
$30k for a CPL? Cost me $70k with my IR. What more do you expect?
I think tmpffisch is closer to the mark and my intuition tells me has has had a CPL for a while now. As others have said, America is worth a look and sure to be cheaper.
Old Acro's advice is gold. Good luck.