Ruth,
You shouldn't need to pay for anything up front, the DAME and DAO will bill it all to Airservices. In fact, Airservices booked my DAME appointment for me. If there's any problems someone at Airservices will get in touch with the DAME/DAO to reassure them that they're footing the bill. The Medibank Health Solutions thing is for your drug and alcohol test and my DAME was able to do that as well.
If you do end up paying for it yourself, I think you're looking at about $700 all up.