Sometimes a supplier in the US either refuses to ship to Oz, or will only do so for rediculous shipping fees. Well, there's a business in Oz that can do it for you using their own agents in the US. I'm sure there are others.
www.priceusa.com.auThey'll buy from a store, even bid for you on eBay, ship within the US, then home. They even act on your behalf for warranty claims.
Their fee is built into the exchange rate - just like a credit card so nothing different there.