The secretary of state is hereby authorized to purchase official flags and official banners of the state of Kansas, and to purchase other Kansas state flags not official in size, provided the dimensions of such other flags are proportionate to the dimensions of the official state flag of Kansas. All such flags and banners shall be purchased on bids by the secretary of state by and through the state business manager or his or her successor in office in such quantity, quality and size as the secretary of state may deem necessary. The secretary of state shall sell such flags and banners and the selling price of each such flag and banner shall be as near to its cost as is practicable plus the cost of distribution, if any.