no, not that much.
If you are a sole trader, you just have to register a business name which costs around AU$126
If you start a company it costs around $1,000 to register a company, plus you have to lodge a company return each year.
I think there are still a lot of relatively untapped markets here in Australia, the downside is that there is only a relatively small population of 20 million in which to market your product or service to.