Ideally, economic analyses and decisions concerning complex agricultural-industrial systems, as represented by crops to fuel alcohol, should be made from systems in operation and not merely from computations found in this article. Currently fuel-grade, fermentation ethanol sells for about $1.75 per gallon in the United States. The computed costs in table 3 are considerably below this value and, hence, must be examined closely in systems in operation. Such important data were not available to the author at the time of manuscript preparation, and interested readers are urged to inquire further.