There's a woman called Jodie-Lea Matheson based in Brisbane who breeds and imports bettas. She is the Australian transhipper for most of the Asian breeders. The importation fee is $25 per betta, plus about $5 in transhipper fees in the country of origin, plus the price of the fish. This money covers documentation, quarantine and her commission for organising the transport of the bettas. I'm not sure whether it includes couriers to take the betta to you. There are discounts available if you buy a large number of bettas. She also breeds bettas and sells at fairly good prices I believe. I have never dealt with her because I'm way up north (so shipping would be outrageous) and currently I don't have enough space to justify spending a large amount of money on pedigreed breeding stock. However she is a member of most of the Australian fish forums.
