Interesting! As a stamp collector, I make many purchases on Ebay. They try to push Paypal, but I pay by other means; I deal only with N. AM. and UK, so pay in dollar or sterling money orders or drafts (or credit card if they take it). I have had one or two buys from Australia; I think I got a draft at my bank, but don't really remember.
Some larger dealers say specifically in their offerings on Ebay that they do not use Paypal, and accept plastic or international money orders. They do not use Ebay checkout.

Many offers are made from Asia and continental Europe, but most require Paypal or Moneybookers (sp.?) because of bank charges on money transfers. I just steer clear of their offerings, except for a few that take plastic.

So far, Ebay has not threatened (as far as I know) to make payment by Paypal mandatory in the U. S. or Canada. I wonder if they are making a test case in Australia.
I haven't checked, but I believe that making Paypal mandatory would contravene U. S. and Canadian regulations as well.