The proceeds of the sale of such lands, after payment of the reasonable costs of the sale, shall be set aside by the commission as a capital improvement fund, to be expended by said commission with the concurrence of the board of freeholders for the acquisition, development or improvement of additional lands for park or parkway purposes or for the development or improvement of existing park or parkway lands.

L.1956, c. 87, p. 180, s. 3.