JAL used to offer a free night at an airport hotel on one leg of Europe-Australia flights, even in Economy class, if you stopped over in Japan. I was once able to have this offer converted into a day room at the airport Nikko hotel at KIX, although the hotel did try to make me check out five hours before the flight's departure

Northeast asian carriers (KE, JL...) have always had competitive rates on Europe-Oz. Typically, through a good travel agent, an Europe-Oz tix costs only a little more than a Europe-Asia one.

Incidentally, KE switched to a two-class configuration on Oz flights a few years ago, not surprising given the emptiness of their F cabin in flights catering mostly to Korean holidaymakers.