Hi Peter
I found this company that may be useful for you. I haven't used them myself yet, but will give them a try next time.
Their rates seem OK.
Basically $28 minimum up to !/2 kg, then $4 for each 1/2 kg after that.
They also provide a US address ( useful if the company won't ship a particular item to Australia) - and can purchase with US credit card if the Australian based credit card is blocked). This can be useful also if the merchant has free shipping within the US.
http://www.comgateway.com/shop-us-on...FUEgpQodiUcA6w
Clear skies
Mark