don't go by the amount calculated at the usps website, it is way off.
i recently shipped two wheels to australia in a box 27x9x27, weighing 10 lbs. the usps website's "postage rate calculator" page gave me two available shipping methods based on my package's length+girth, which was more than 79' but less than 108'- both available methods were global express guaranteed. one was for documents, at $104, and the other for non-documents, at $268. when i took the box to the post office, the rate turned out to be $57! apparently the usps website's rate calculator tool incorrectly lists the size restriction of plain global express (not guaranteed) to 79' when in fact it is 108'.
i recently shipped a 56 c-c frameset in a box with a combined length+girth of precisely 108', and there was room enough for a 57 c-c frameset. so for a complete bike of no more than 57 c-c, you should be able to ship it to australia in two boxes for a total of around $160.
ray dobbins
miami florida