In addition to the declarations required by section 2672 of this title, any commodity in package form, the package being one of a lot containing random weights, measures, or counts of the same commodity and bearing the total selling price of the package, shall bear on the outside of the package a plain and conspicuous declaration of the price per single unit of weight, measure, or count. (Added 1967, No. 102, § 20, eff. April 14, 1967.)