Anne, what about ebay? I used to find so much clothes BNWT (Brand New With Tags) for all ages, admittedly much more before than now. I don't live near anyone who can hand me things down so sources like that are useful. Or "nearly new" sales as they are called here, organized by parenting groups.
But, on-line (whichever way) or in-store my best sources are Marks&Spencer for their ratio of quality/price, Pumpkin Patch is great too although they do colors a bit muted for my taste (and my boy looks best in bold colors like both parents )
These are no Aussie brands, but I know M&S do have stores overseas, perhaps in Oz too?
Supermarket chains here do nice children's clothes, and I do sometimes stock up there, but I always cringe when I think how on Earth could something be produced in, say, China, shipped all the way to the UK, sold for as little as £4 (and still overpriced because in no time it'll be marked down) and STILL make profit...
I must admit, life is much easier now that 5 days of the week we only take care that school uniform is clean and tidy, which effectively leaves us with the need for weekend-worth change of clothes (but covering various types of events, from casual to dressy, e.g playgroups to going to concerts. Minimalist wardrobe is so much easier to manage!