In Qld about $18,500.00 per year for a B/Double Prime Mover and 2 trailers.
About $8,500.00 for a single and trailer.
I have never run shuttles but I think 600,00 might be a bit high.
Any driver doing more than about 250,000 a year would be pushing the limits. That is 1,000 klms per day 5 days a week 50 weeks a year. (I did once put 570,000 klms on a truck in 2 years, but I would never want to do it again.)
1,000 klms a day 5 days a week is not easy and 6 days a week is right on the limit of anyone's endurance.
Don't forget the tax on fuel which is also supposed to go to road maintenance. Most of these B/Doubles are on around 1.6 to 1.8 klms per litre. So around 140,000 litres per year.
In 1998 I spoke to an RTA guy on the weighbridge at Marulan who said that each night on the 8 hour night shift they had about 3,000 trucks through each direction. That was one inter capital highway so yes the road transports contribution to infrastructure is sizeable.