The circuit, chancery and county courts shall make allowance to the clerks thereof of all needful sums for supplying the offices and courtrooms with necessary stationery, furniture, books, presses, seals, and other things necessary for the same, and for the safe-keeping of the books, records, and papers belonging thereto; and such allowance shall be certified to the board of supervisors. Provided, however, that in no event shall said circuit, chancery or county courts be allowed to purchase furniture in excess of five hundred dollars for any one year without first securing the approval of the board of supervisors of the county.