If you wanted to take out a mining licence in Victoria you are best to look at a Prospecting Licence, not a Mining Licence. Its a little easier for a claim of up to 5 hectares. But..........you will have to go through Native Title, take out $10 million of public liability insurance, Pay fees amounting to about $2000.00 to register the claim and pay a minimum $10,000 bond for rehabilitation of the land.
I would never discourage anybody taking out a claim and am more than willing to help you if you wish to go down this path, but first you need to have a reasonable idea of what you expect to find.
On top of that there are equipment costs, and other running costs such as fuel etc, and the costs of securing your claim. You would need to collar the hole and put a hatch of some sort on it to keep unwanted people and animals out.
My rough estimate is 25k to start up a claim.
In the current environment you would be better to set up camp where you want to dig and spend a month digging the hole out. Then test the ground. If you do o.k. then maybe register a claim, if not, then you haven't laid out a small fortune for no reward.