For the purposes of this chapter, the term:
With regard to any determination of the cost of cigarettes to a wholesaler or retailer, a fractional part of a cent equal to 1/10 of 1% or more shall be rounded off to the next higher cent. Except as provided in § 28-4522, discounts granted for cash payments or electronic fund transfers shall not be used to reduce cost determinations.
Notwithstanding § 28-4522, articles or products given gratis or payments made to a retailer or wholesaler for display, advertising, or promotion purposes shall not be considered in determining the cost of the articles or products.
D.C. Code § 28-4521