There are only two ways that I know to have a large collection in Australia.
1. Lots of time - you've been in the hobby forever and/or you have been buying, selling and trading for years and place zero value on the time you've invested.
2. Money - lots of it.
Most people I know fall into the second category, it might have taken them 6 or 7 years, but whether they realise it or not, they've pumped $150k+ into the hobby.