In determining the cost of cigarettes to a wholesale dealer:
1. A fractional part of a cent amounting to 1/10 of 1 cent or more in cost to the wholesale dealer per carton of 10 packages of cigarettes must be rounded off to the next higher cent.
2. The invoice cost of cigarettes purchased at a forced sale, bankruptcy sale, closeout sale or other sale outside of the ordinary channels of trade must not be used to justify a price lower than the replacement cost of cigarettes to the wholesale dealer in the quantity last purchased through the ordinary channels of trade.