I looked up driving from Wollongong to Perth after just driving to Melbourne and Back
From Wollongong to Perth, I was looking at 36 hours of continuous driving IIRC. For Perth to Melb, it's 37 hours... So four days of driving if you do 8 hours a day. If you're the only driver, that's VERY tiring. You'll want to break it down, and take a whole week to drive there. And then a day or two to recover...
Secondly fuel prices. I took my XR6T down and back with 4 adults, we were doing 8.5L/100KM pretty much. Seeing how it's 3,400KM there, and the same back, if you average my fuel economy, and get fuel at around $1.50 a litre, you're looking at $433 each way to drive it... (I think)...
I run 98 or 95, and most of the time I was finding it at $1.60... (And I copped a bad tank of fuel that put economy out at 13L/100km!)
So it can be expensive, but if you have multiple people, it's cheaper. But it can get VERY draining just driving...
My trip to Melb was fine, went past very quickly... The return trip, I think I'd prefer chineese water torture...