Jaki,
I don't know where you are in Oz, but a correspondant of mine who lives in Australia, talked about a family history centre that he could go to to look up records and I understand they do batch orders periodically. He even kindly ordered a marriage certificate for me through the system (as I'm also outside of the UK) and sent it on to me. I think it might have been in Sydney, but it's well worth looking through your directories to see what is available.
Jane