Such board may exercise, on behalf of the municipalities acting jointly by which it is appointed, all the powers of each of such municipalities granted by the Revised Airports Act, except as otherwise provided in the act. Real property, airports, restricted landing areas, air protection privileges, or personal property costing in excess of a sum to be fixed by the joint agreement, may be acquired, and condemnation proceedings may be instituted, only by authority of the governing bodies of each of the municipalities involved. The total amount of expenditures to be made by the board for any purpose in any calendar year shall be determined by the municipalities involved by the approval by each on or before the preceding May 1, of a budget for the ensuing fiscal year. Rules and regulations provided for by subdivision (2) of section 3-215 shall become effective only upon approval of each of the appointing governing bodies and the Division of Aeronautics of the Department of Transportation. No real property and no airport, other air navigation facility, or air protection privilege, owned jointly, shall be disposed of by the board, by sale, lease, or otherwise, except by authority of all the appointing governing bodies, but the board may lease space, area, or improvements and grant concessions on airports for aeronautical purposes or purposes incidental thereto, subject to subdivision (3) of section 3-215. This section shall not be construed to affect the obligation of a lessee to pay taxes if taxes are due under sections 77-202, 77-202.11, and 77-202.12.