I would have him Google quilt shops in Melbourne and see what he can find. When I went on a cruise back in 2010, I had a hard time finding some when we made a few stops. However, the prices may be higher than here, though take in consideration that they sell by the meter (~40 inches vs our 36 yard) and the exchange rate is $1AUD = 0.75 USD.
There are several shops online in the US that are selling Aboriginal fabrics, like HeartSong Quilts.