Looks like a good deal, $6 cheaper than last time, but only girls available at this price.
Size 4 is a 116pk (9 to 14kg), size 6 is a 96pk (15kg+)
Note that these are nappy pants, not regular nappies.
Huggies Ultimate Nappies Size 1 Newborn 216pk, $42.50 Delivered with Subscribe & Save & Prime or $45 for those without prime. Also appears to be a good price. They are currently on special for $25 for the 108pk at Coles.
Edit 15/5 130am: Boys Size 5 now available for the same price. Thanks to OzBargain F5er