Section 3B. Seven or more persons, residents of the commonwealth, may associate themselves as a corporation, association, society or company engaging in cooperative purchasing of goods for the personal use and consumption of the stockholders thereof, members of their families and their guests. A corporation organized under this section shall, in pricing its goods, make no provision for earnings, the accumulation of capital, or operating costs, and shall provide for its operating costs by levying upon its shareholders a direct-charge therefor, on a pro rata basis. The words ''direct charge'' and the word ''cooperative'' shall form a part of the name of the corporation, and for the purposes of this section and sections four to nine, inclusive, the words ''association'', ''company'', ''society'' and ''union'' shall have the same signification and shall import a corporation. The corporation shall be formed as provided in chapter one hundred and fifty-six B, with shares having par value, and shall be subject to the provisions thereof so far as consistent with said sections.