The act by an industry member of giving or selling outside signs to a retailer does not constitute a means to induce within the meaning of section 105(b)(3) of the Act provided that:

(a) The sign must bear conspicuous and substantial advertising matter about the product or the industry member which is permanently inscribed or securely affixed;

(b) The retailer is not compensated, directly or indirectly such as through a sign company, for displaying the signs; and

(c) The cost of the signs may not exceed $400.