the prices I used were actual prices for this fall for certified organic crops,
I have only heard  $.50 / bu corn premium for nongmo, and maybe $2/ bu sb nongmo.
A good strategy is if you can use hay, to put transitioning ground into hay for the 2.5 years and then into corn for first year certified organic .  There are other rotations and market possibilities, keep looking and ask around in organic circles.  Keep looking.
thanks