I had a similar situation about 6 weeks ago; was really worried; but it turned out the buyer had recently moved to Sydney from the UK & had forgotten to change their address. Maybe this is what has happened for you?
My sale proceeded smoothly. Maybe the ebay system realises they are bidding from within Australia? Maybe they are a tourist currently here?
Some years back A UK bidder also won one of my auctions. I don't post overseas & have all blocks in place. The item was to be a gift for a friend in Australia; But I still can't fathom how the Brit was able to bid! No correspondence was entered into prior to the auction end & then I had to guide the UK buyer through the sales process & ended up giftwrapping the item for the Aussie gift recipient. It too ended well. So there are many scenarios that might apply to your bidder. Take them @ face value until proven otherwise - Unless they are from Nigeria!
