Supermarketdeals.com.au was not really impressive so far. But I think I found a great deal on this site:
46pack (10kg+) —> 0.17 per nappy
40pack (12kg+) —> 0.20 per nappy
35pack (16kg+) —> 0.24 per nappy
Each pack is $8
You can buy 10 packets of one product only … free shipping when you order over $30 and pay via paypal (see voucher code) until 14/06.
This should be easy to achieve with nappies :-).
Just ordered 10 of the 12+ packs and 10 of the 16kg+ … must be a massive parcel.