does anyone know what the cost of corn would have to go to before it would make corn based ethanol more expensive than fossil fuels.

i realize it is a dynamic question becuase gas prices change as well. but assume fuel prices were static and this was a question for todays prices. how high could corn go before ethanol was not worth it at least using corn.

and lets say the government was devaluing the us dollar would they subsidize corn and to what extent. the us is the largest supplier of corn in the world. it would solve a lot of debt issues.

thanks