I took a trip from Sydney to Perth in May last year and had a good time. It is expensive, but it's not marketed as a mode of transport. It's a train cruise, fully catered, and with numerous off-train excursions included. I think my solo accommodation aboard fare was in the mid $3k range. That's AUD so you can do your own conversion to your own.About $A 4,000 depending on choice of accommodation.