Hi Roger (and other APUGers)
I live in Melbourne and have also purchased film from overseas, mainly J&C. The Australian Customs Website (www.customs.gov.au) has a really detailed explanation on importing goods from the internet. There is a difference between using postal services and courier services as couriers can charge their own fees. Customs also include the postage as part of the overall costs in calculating import costs. I haven't had any problems with film I have received to date. I also purchased camera equipment from Canada which came to over Aus $1200 (I had the shipment boxed into two lots as I didn't know about the split packaging rules at that time) and somehow managed to avoid customs duties so I think it is also a bit of hit and miss. I would think though they might be a bit more vigilant at the moment with the Commonwealth Games coming up so may be a bit more thorough with their checking, or maybe too busy to care.
I have to agree on the expiry date of films here. If I purchase from Vanbar they are pretty good, but if I use my local I have actually purchased film and found it is already at it's due date or only a couple of months off. At least Vanbar give a discount on film at it's due date.
I have been trying J&C's film and have also purchased some Efke, neither of which you can purchase here. The cost of those films is amazingly inexpensive even with postage included. If I was only purchasing Kodak, Fuji or Ilford I don't think I would be saving much by getting them from overseas depending on the postage costs, but with some films such as J&C and Efke it seems to be a much cheaper alternative. J&C also stamp on their parcels "Photographic Film, Do Not Xray". I'm not sure if they stock supplies that you need but for black and white film they certainly have some good alternative choices.
I might also have to take a look at some of the other sites mentioned in this post. I agree it would be great to get it from local suppliers but unfortunately the choice of product isn't always available.