If that was true then E10 wouldn't be cheaper than unleaded; it would be more expensive if the ethanol was the expensive component in it's mix, but it's not.
It's jumped by nearly 20 cents a litre and this happened around the time Caltex pulled out of e-flex. They're simply charging it because they can, which is fkin shit for people like me who got on it a couple of years ago and gave them a reason to even stock it. They're not supposed to be making that much money on the shit and economy of scale says it should be getting cheaper with more widespread use, not more expensive.
I bet you if another chain came out with an E85 mix they would instantly take 20 cents a litre off it.