For the purpose of sections 51-12-08 through 51-12-14 the worth or value of any thing advertised is the prevailing market price, wholesale if the offer is at wholesale, retail if the offer is at retail, at the time of publication of the advertisement in the locality wherein the advertisement is published.

No price may be advertised as a former price of any advertised thing unless the alleged former price was the prevailing market price as above defined within three months next immediately preceding the publication of the advertisement or unless the date when the alleged former price did prevail is clearly, exactly, and conspicuously stated in the advertisement.

This section does not apply to any publisher, owner, or employee of a newspaper, magazine, broadcasting or cable station, advertising device, or other publication by any means of communication, who publishes an advertisement in good faith, without knowledge of its false, deceptive, or misleading character; nor to any owner, manager, or employee of an advertising agency or a printer that prepares, places, or prints an advertisement in good faith, without knowledge of its false, deceptive, or misleading character; nor to any employee of the person who offers the advertised thing if that employee in good faith relied on the statements of the person and did not have knowledge that the statements were false, deceptive, or misleading.