The cost and expense of acquiring or acquiring and improving new property (including any amounts necessary to comply with Section 31929 and any amounts necessary to discharge any other lien or charge on said new property) shall be paid from district funds to the extent authorized by the board and the remainder, if any, from city funds. If for any reason the legislative body is unable or unwilling to appropriate from city funds the moneys needed for such purpose, the substitution proceedings shall be abandoned prior to the adoption of any resolution of implementation.