Not sure how they're doing it in Australia, but some of the French consulates in the US indicate that if you are going to France as an "entrepreneur" that you should apply for a "visitor visa" (i.e. one that does NOT permit you to work).
The auto-entrepreneur website has confirmed that with a visitor visa, you can then go to the prefecture to get cleared to set up a business (they have to confirm that you meet the entry requirements for the particular line of work you're going into) and then come back and register as an AE. Check this site for details:
Portail Officiel des Auto-Entrepreneurs (it's all in French). I'm not sure if you would be able to change your status to a "commerçant" after entry on a visitor visa, but if you chose not to go the AE route, that's what you'd need to do.
We had at least one poster here on the board who got the AE registered and then went to the prefecture to renew their carte de séjour and were turned down and told to leave the country. Not sure what happened there, but it's very important that you tell the consulate about your plans to start up a business when you apply for your visitor's visa. (I would first check to see if that's what the consulate in Australia is advising, because I notice at least one of the US consulates has changed the advice on their site.)
With the visitor visa, you'd have to show resources to be self-sustaining for your first year in France - and have a paid up health insurance coverage for that period of time, too.
Cheers,
Bev