A mate of mine just recently had his car tuned in sydney for E-85 and was told by the tuner that the two locations in canberra (nicholls and kambah) is not E-85, it is more a blend of 65% ethanol and the rest unleaded.
From what he was saying there is a major power differance between getting proper E-85 from a supplier like Trojan etc can be up to 30% being that E-85 being higher in power output compared to the "flex fuel" (@ nicholls and kambah)
I know you can get 44 gallon drums for a reasonable "ish" price from sydney and fill when you need to.
But in saying that you will then become your very own servo.