The board of county commissioners of Johnson and Sedgwick counties shall appoint a qualified person who shall be known as the county purchasing officer, and who shall hold office at the pleasure of the board. The board of county commissioners shall fix the compensation of the county purchasing officer and make allowances for clerk hire and the expenses of conducting the office of said purchasing officer. A surety bond issued by an insurance company authorized to do business in this state in a sum determined to be necessary and proper by the board of county commissioners shall be furnished as required by Kan. Stat. Ann. §§ 19-4202 and 19-4203, and amendments thereto, to cover the purchasing officer, conditioned that such officer will honestly and faithfully perform the duties of the office, and that all supplies and equipment purchased and agreements entered into for said county shall be purchased at the lowest and best price obtainable. Such bond shall be approved by the board of county commissioners. The cost of such bond shall be paid by the county from the county general fund.