If one just circumnavigates Australia on Highway 1 with no off trips its around 15000 KLM. So the average car pulling a van may get 7 KLM to 1 litre.
7 KLm into 15000 = 2142 Liters in fuel x Average 1.80 per litre. = $ 3857 Just for fuel.
Add car servicing, breakdowns, tolls and what not, one is looking at some big money just to run the car. Pray to god one does not breakdown in the middle of outback Queensland and needs towing. Fuk me, better just to burn the foking rig.
I'm being conservative here as most punters crank 20 K KLM going around and way up north fuel can run at $ 2 per litres. In the cities around $ 1.40.
Add Caravan Park fees, food and lots of piss one drinks on the trip its advisable to have a shite load of cash assigned to the road trip and not worry about the cost.
Just spend freely and enjoy, If one worries about what it will cost just don't bother going. In Cairns City the main caravan park charges $80 per night in high season just to park ones shitty van.
To be cost effective the longer one is on the road the much better as it all pans out.
Also these days there are many brilliant free camps where one can bunk up for the night for free so outside the cities many make use of these.
That's my go, I can just camp anywhere as I'm self sufficient with my rig.
I do my own oil changes as well so there's fair money saved there.
Oh yes, the great Aussie road trip. Ain't been around Australia for 18 years.
I'm going again. Far North Queensland is the go.