Looking at Freestyle, it's roughly $80US for 10 rolls, plus $40USD for postage to get it here. So that's $120USD, then you mail it to Kansas, then it's $90USD to process that film, and then around another $40USD to get it mailed back. So all up that's $250USD, ignoring the cost of mailing those rolls to Kansas from Australia. That's $389.59 in Australian dollars, at this moment. So I can expect to pay around $40 per roll of kodachrome, from start to finish.
Actually, I'm not posting this to complain, I love kodachrome to bits, and the dozen or so rolls I have managed to shoot in my time have been absolutely lovely. I've got boxes of my mum's kodachromes from her time abroad, and my grandfather's kodachromes of the riverland, taken between 1950 and 1980, and they're of dear importance to me. It's nice to add to the box of family heirlooms. But If you can shoot this film for less than $40 a roll, please take advantage of it. There are Australian photographers who foot the bill, but I'm hard done to pay the $8 for a roll of HP5 most of the time.