I AM on the East Coast.  Price of E15 is $0.50/gallon less than E10 (E87).  

I will have to think about where I can buy non-ethanol E87.   I am sure it is higher. I will have to find a station and compare prices. 

You are correct that the price benefit may be overstated.... there are people that buy E10, even though E15 is available.   ;)