The Australian domestic market has, as mentioned, only four real airlines, of which just two offer real competition for the business traveller. Because the distances are so vast, travelling between main centres in Oz has to almost exclusively be done by flying (500 miles between Syd and Mel) and so there is a large number of customers who fly between cities that in the UK we would drive or take the train. Fares are therefore much higher but my impression has always been that the service is a bit better on QF/VA compared with BA's domestic or SH offering.
Must keep in mind though that the chance of flying in Y between say Syd and Mel for the cost of flying between say LHR and EDI is nigh impossible. Far lower fares here and of course very cheap avios offerings (8000 plus £17.50 taxes) so I guess you get what you pay for.