For purposes of this chapter:
(1) The tax imposed by chapter 20 of title 44 shall be deemed to be a part of the original cost of cigarettes to the wholesaler;
(2) The invoice or replacement cost of cigarettes, cigars, smoking tobacco, chewing tobacco, snuff, and other tobacco products, to any wholesaler or retailer, shall be deemed to be the minimum price in this state at which the products may be purchased in this state by the wholesaler or retailer; and
(3) Merchandise given gratis to a wholesaler or to a retailer for display, advertising, or promotion purposes, or otherwise, shall not be considered in determining the cost of merchandise to the wholesaler or retailer, as the case may be.