I was not aware that the Broken Hill aircraft had achieved 35,000 hrs TT, so I guess thay are not aging aircraft, but merely too expensive to operate in comparison to the PC-12.
We've been thru the arguments of economics before and nothings changed.
One day when a RFDS crew is killed in a PC-12 then they will say and I quote from Dick Smith "law of averages" and "afordable safety"
Safety is less of a concern than it it with High capacity RPT followed by low Capacity RPT then Charter and then AirWork ops. Enjoy your PC-12 (its a fine aircraft) but when the next thunderstorm and lightning strike imobilises your s/e aircraft engine reflect as you glide towards the pitch black ground with your 26g high impact crew seating that the insurance company will have a cheque on the bosses desk the next day. Pity about you!
PS: Scary thought, PC-12's for Air Ambulance at Essendon, you bet just wait and see, regardless of contracts it will happen. The $$$ sign always wins.