I bought mine from a bookshop in Perth for $35 a couple of years ago
I guess that's why they can do free shipping.
I also buy books from the Book Depository in UK, and they always ship for free, all the way from the other side of the world. Their prices are also generally cheaper than Booktopia. I've given up on Amazon, with the US$ where it is against ours. Having said all that, if you know your prices, there are still bargains to be found.