Australia was historically a smaller market that is physically far away from America and ( and had fewer trade links with Japan). Australian TVs were PAL while America and Japan used NTSC, which added a whole other layer of complexity. This meant that PAL production lines were geared towards the European market, with Australia getting the excess. Those copies then had to be shipped across the Pacific Ocean, which is expensive. Combine a smaller, lower-priority market with longer, more complex shipping, and manufacturers charged more to make a profit. This set a standard price for Australia which persists even today.