All road material, brick, tile, concrete and other goods and materials prepared or made at a joint industrial farm and workhouse that are not needed for the purposes of the joint industrial farm and workhouse shall be offered for sale at a price to be fixed by the commissioners of the district. In offering such material for sale, preference shall be given to the counties forming the district of the joint industrial farm and workhouse and to the cities, boroughs and townships in the joint district. All moneys so received shall be applied toward paying the overhead expenses of the joint industrial farm and workhouse.