Here is an interesting link regarding E85.
http://www.fuelgaugereport.com/
Notice the "adjusted" price for E85 on the far right. When BTU's are taken into consideration. It no longer looks like such a bargain.
Quote form AAA site
**The BTU-adjusted price of E-85 is the nationwide average price of E-85 adjusted to reflect the lower energy content as expressed in British Thermal Units - and hence miles per gallon - available in a gallon of E-85 as compared to the same volume of conventional gasoline. The BTU-adjusted price calculated by OPIS and AAA is not an actual retail average price paid by consumers. It is calculated and displayed as part of AAA's Fuel Gauge Report because according to the Energy Information Administration E-85 delivers approximately 25 percent fewer BTUs by volume than conventional gasoline. Because "flexible fuel" vehicles can operate on conventional fuel and E-85,the BTU-adjusted price of E-85 is essential to understanding the cost implications of each fuel choice for consumers.