Section 211. Sales between Affiliated Interests, etc.--In determining sale price of taxable sales where, because of affiliation of interests between the seller and buyer or for any other reason, the sale price from a sale are not indicative of the true value of the article sold or the fair price thereof, the department shall prescribe uniform and equitable rules for determining the amount of constructive sales prices upon the basis of which the tax shall be levied. Such rules shall provide for a constructive amount of a sales price for each such sale which shall equal a price for such article which would naturally and fairly be charged in an arms-length transaction in which the element of common interests between buyer and seller or any other element causing a distortion of the price is absent.