(a) In determining cost to the wholesaler and cost to the retailer the court shall receive and consider as bearing on the bona fides of such cost, evidence tending to show that any person complained against under any of the provisions of the Unfair Cigarette Sales Law purchased the cigarettes involved in the complaint before the court, at a fictitious price, or upon terms, or in such a manner, or under such invoices, as to conceal the true cost, discounts or terms of purchase, and shall also receive and consider as bearing on the bona fides of such costs, evidence of the normal, customary and prevailing terms and discounts in connection with other sales of a similar nature in the trade area or state.

(b) Where a cost survey pursuant to recognized statistical and cost accounting practices has been made for the trading area in which a violation of the Unfair Cigarette Sales Law is committed or charged, to determine and establish on the basis of actual existing conditions the lowest cost to wholesalers or the lowest cost to retailers within the said area, the said cost survey shall be deemed competent evidence in any action or proceeding under this law as tending to prove actual cost to the wholesaler or actual cost to the retailer complained against, but any party against whom any such cost survey may be introduced in evidence shall have the right to offer evidence tending to prove any inaccuracy of such cost survey or any state of facts which would impair its probative value.