http://www.bus4wdhire.com.au/21-seat-bus-hire.htm
Based of this^ info, driving from Melbourne to Albany and back will cost $1700 in excess km and use about 1500 litres of fuel which would be around $2800.
http://www.crownrentals.com.au/rcm/step2.php#results
Based on this^ info the total cost of hire would be about $2000.
There's $6500 just for the bus and fuel and you won't be sleeping in the bus. Ain't nobody got time for that homeless sh*t. Gotta wash your ass somewhere not to mention having to jerk the gherkin.
Accomodation, food and beer can be done for minimum $200 per day per person. There's $2200 per person.
Not including getting into rw, misc money or emergency flights back, we're already up to $17500 in total or $3500 per person for 5 people to go.
Rough numbers but pretty close to what it would cost.
It might be better to hire a freaking giant rv? Cos I like googling and adding sh*t up, I'll see if I can work that out.
I changed my mind I cbf adding up anything else but I did find this.
There is rv's that sleep 6 adults with unlimited km for about $1500p/w. That would cut about $700 off the total hire and obviously halve the daily per person cost.
That's much more reasonable.