You are dead right Bob, like I said naive.
It's nearly 6 months ago so it's hard to remember all the details.
From my experience ordering other things online in .au, the postage is either added to the tally in the order form on the web site, or in the order confirmation email (in which case you have a chance to cancel the order) or in unusual cases someone gets in touch via email.
This is what I received in the confirmation email Feb 2nd:
I was assuming that someone would be in touch with me shortly since I was already in touch via email with them, and delivery charge was obviously not going to be zero.
I guess the warning bells should have gone off when I first tried to order. The website threw a fatal Cold Fusion error half way through the process and I was left with no indication of whether my order was successful or not. Had to get in touch via email, and was advised to retry.