Boards of county commissioners within the state of New Mexico are hereby authorized to sell, transfer and convey to any city, town or village located within such county, or to any agency or department or commission of the state of New Mexico, operating facilities within such county, such public buildings and lands on which such buildings are located, or such other lands, lots and additions belonging to the said county, whenever the same are no longer deemed necessary for county purposes, without appraisal, at private sale, for such sum as the said county commissioners may in their judgment determine.