Cotton on Kids has a sale on some - what I guess is - end of season, end of range stuff, but there are great prices, and if you can find alternative uses for them, they're a bargain.
For example, the Stationary Sets are listed as 'back to school', but if you can use a ruler, book and pen set for something else, the $14.95 pricetag may be a bit rough, but the reduced price of $5 is a lot more doable.
They also have a range of Tulle skirts on sale, in a variety of colours. I was at a market recently and saw skirts very similar to these reduced for $20 - I didn't buy one as I thought they were way too much, but at least these are only $10, (although reduced from $24.95) and I'm sure they'll be loved by your little princesses!
Shipping from Cotton on Kids is free for orders over $50, otherwise you're looking at $10 for shipping within Australia.