I know a coin shop or ebay is the most obvious, but do you have other go to sources? I like to support the LCS but occasionally they don't have what I am after, or are just wanting too much. Currently looking for a 1966 wavy 20c on behalf of someone else who will be giving it as a gift.
I've been finding coin auctions to be a really good option. Noble Numistatics (noble.com.au) is having one in November. There seem to be at least a one or two other options in Sydney, Melbourne, and Brisbane. Edlins in Canberra is having an auction this weekend, though I'm finding the catalog for this auction to be kind of thin pickings. Roxby's(?) is having an auction in Brisbane in a couple of weeks. Most of them give you the option to submit a bid by mail/email, but watch out for shipping costs. There are also a few places through icollector.com that have coin auctions in Australia. I'm vaguely thinking about heading into Sydney the weekend after next for the ANDA show. Haven't been before, but it seems like it could be interesting.