The immigration form that you are required to fill up at immigration, has a specific question (Question number 5 i believe) that whether you have more than 10000 AUD or equivalent. If you check yes, most likely the customs officer will just have a look, count and take a record. It's good for you because you will have a record for tax free wealth.
Is it only for FIRST arrival? Or you can do that every time you arrive? Thats one huge flaw in the immigration.