Providing group purchasing agency services, namely, negotiating discounts and rebates on pharmaceutical, medical, surgical, cosmetic, plastic surgery, and office products and services on behalf of its members, namely, physicians, physician offices, ambulatory surgery centers and other facilities; providing sales and purchasing information collected with respect to physicians, physician offices, and other institutions where cosmetic surgery is practiced in connection with the delivery of the aforementioned group purchasing agency and other services to manufacturers and distributors of medical and cosmetic products and services