Any lease, sale, contract, or other disposition of any or all lands referred to in Section 59-9-29 may be made upon such terms and conditions and for such consideration as may be found to be adequate by the county port authority, and approved by the board of supervisors in orders or resolutions authorizing same, and the covenants and obligations of the lessee or grantee to make expenditures in determined amounts, and within such time or times, for improvements to be erected on the land by such lessee or grantee, and to conduct thereon industrial operations in such aggregate payroll amounts and for such period of time or times as may be determined and defined in such lease, deed, contract or other disposition, shall constitute and be deemed sufficient consideration for the execution of any such lease, deed, contract or other disposition. Any such lease granted for industrial or harbor operations under paragraphs (a) and (b) of Section 59-9-19 may contain an option to buy at any time and/or upon termination thereof, and shall, however, contain reasonable provisions for the termination of the lease or reversion of possession of the land and all improvements made by lessee or grantee to the facility, including personal property, unless previously agreed to, in the event of default on the part of the lessee or grantee of his or its obligation or covenants under such agreement.