Hi,
I don't "add" shipping overseas in my listings - my items are too varied in weight to do that. But I do say in each listing "overseas shipping- contact me"
I have had quite a few sales to Australia in the past - but with the increased postal rates, that may not happen - just lost one yesterday to Australia.
I recommend it - never had a problem with delivery.
ETA - for anyone who does not know this, you can calculate your postage anywhere in the world by going to usps.calc - I love it!