The director may establish and maintain at any institution or camp under his jurisdiction a canteen for the sale to persons confined therein of candy, nutritional snacks, toilet articles, sundries, and other articles. The canteen shall operate on a nonprofit basis. However, if sales should exceed costs, the surplus shall be deposited in a special fund, to be designated “Benefit Fund.” Any moneys contained in such fund shall be used for the benefit of the wards resident at the institution or camp.