I addressed this in another comment more fully. For this version though, consider that even though it might be possible to do such a thing, the vast majority does not. You could potentially be sneaky about this, but the effort would not be worth the small savings you would make.
The current HELP/HECS system doesn't just work on paper. It's been used successfully for a while.
Remember, we are about repayments starting at 2% at 50k AUD (35K USD) and going up to 8% at $107+ AUD (77k USD). This is not a crazy, crippling payment. It is not worth making substantially less in your job in order to save such (relatively) small sums.
Australia is not a welfare state. We rank 5th in economic freedom [1] (USA is at 18). While the nation does have many problems, I do believe that Australia performs decently at balancing a free market and government support. While we used to have completely free universities, I believe that the current loan program is a decent midpoint between the US and European systems.