Today Amazon have launched a mid-year sale with a number of offers across their range. It looks like there are quite a few different LEGO deals available within the toy category.
You can check out this page to see all of the current deals. Amazon sales usually have rolling deals with new stuff added during the duration of the sale. Check back regularly to see if anything new is added.
Alternatively, head on over to the Bricking Around Amazon offers page where you can search and sort all Amazon Australia listings to find the biggest discounts.