Whenever the board of county commissioners shall sell the county farm, county infirmary, county home or any part thereof, and any buildings thereon, as provided for herein, said board may use the funds derived from such sale, or any part thereof, to purchase land and to erect a suitable building or buildings thereon, and to make other necessary improvements, and provide necessary equipment for the establishment of a home for the aged: Provided, That in counties having a population of more than twenty-four thousand (24,000) and less than thirty thousand (30,000) and in counties having a population of more than sixty thousand (60,000) and not more than one hundred thousand (100,000) any moneys received from the sale of a county farm and site may be placed in a special building fund and used without regard to limitations prescribed by the budget law for public buildings or structures and sites therefor as the board of county commissioners shall deem to be necessary for the county for public county purposes; and may be used in combination with other funds for such county buildings.

Any funds not used as provided by this section shall be placed in the county general fund.