Section 18V. A district agreement established under section 18Q or any amendment to the district agreement may contain provisions authorizing any member municipality to sell, lease or license to the regional 911 emergency communication district any facility, building and any land appurtenant thereto or used in connection therewith or any other property useful for the purposes of the district. Notwithstanding section 3 of chapter 40 or any other general or special law to the contrary, any member municipality may authorize a sale, lease or license. For a sale, the terms and time of payment and the method by which the municipalities other than the selling municipality shall be assessed for payment shall be established in the district agreement or amendment; provided, however, that in no case shall payments be made which shall exceed 25 years. For a lease or license, the terms and time of payment and assessment shall be established in the district agreement or amendment. The term of a lease or license shall not exceed 25 years and may contain provisions for the extension of the lease or license for an additional term not to exceed 25 years at the option of the regional 911 emergency communication district board.