(a) The provisions of this article shall not apply to sales made: 1. As an isolated transaction and not the usual course of business; or2. Where cigarettes are advertised, offered for sale, or sold by any fiduciary or other officer acting under the order or direction of any court.(b)1. Any retail dealer may advertise, offer to sell, or sell cigarettes at a price made in good faith to meet the price of a competitor who is selling the same article at cost to him as a retail dealer. Any agent or wholesale dealer may advertise, offer to sell or sell cigarettes at a price made in good faith to meet the price of a competitor who is rendering the same type of services and is selling the same article at cost to him as an agent or as a wholesale dealer, as the case may be. The price of cigarettes advertised, offered for sale, or sold under the exceptions specified in subdivision (a) of this section shall not be considered the price of a competitor and shall not be used as a basis for establishing prices below cost, nor shall the price established at a bankruptcy sale be considered the price of a competitor within the purview of this section.2. In the absence of proof of the price of a competitor, the cost of the retail dealer or the cost of the agent or wholesale dealer, as the case may be, which is established pursuant to section four hundred eighty-three of this article, may be deemed the price of a competitor within the meaning of this section.(c) In establishing the cost of cigarettes of the retail dealer, agent or wholesale dealer, the invoice cost of said cigarettes purchase at a forced bankruptcy, or closeout sale, or other sale outside of the ordinary channels of trade, may not be used as a basis for justifying a price lower than one based upon the replacement cost of the cigarettes to the retail dealer, agent or wholesale dealer in the quantity last purchased through the ordinary channels of trade.