Why do you want to go to Perth?
In a previous life I worked a summer season down in Oz, we never operated to Perth as we only had 2 engines on our B737's, Dan Air were operating the Perth routes with their B727, but Perth is a very popular, and apparently beautiful, destination.
Why go to Perth? ... Perhaps for similar reasons that Air Mauritius, ANZ, Cathay, China Southern, Emirates, Qatar and another M. Eastern carrier, Garuda, Singapoore Airlines, SAA and Thai, to name but some, go to Perth ... Because people do want to go to/from there.
Perth is the hub that serves, pretty much, half of Australia, just look at all the feeder routes, many operated by Qantas and/or QantasLink, in/out of Perth, with an aircraft the size of a B787 I would suggest that such a route is a winner.