If the board of directors of Tobacco Associates finds that it is not reasonably feasible to base the authorization, making, or collection of an assessment on a "per acre" unit, it may by an affirmative vote of not less than two-thirds of its members, which vote shall include the affirmative vote of not less than two-thirds of the board members who were elected by South Carolina farm organizations, use a "tobacco poundage" unit as the basis for the authorization, making, or collection of an assessment. No assessment may exceed fifty cents for each one hundred pounds of the flue-cured tobacco marketed by each farmer. The amount of any alternate assessment based upon a "tobacco poundage" unit as permitted by the provisions of this section must not be related to or limited by the amount of the assessment which could be authorized, made, or collected if it were based upon a "per acre" unit.