The authority and its incorporating unit or units may only enter into a contract or contracts under which the authority will acquire property contemplated by the terms of this act and lease the same to the incorporating unit or units for a period not to exceed 50 years or, if the authority issues refunding bonds pursuant to section 11k, the authority may enter into a contract or contracts under which the authority will own or continue to own the property acquired, in part or in whole, from the sale of the bonds to be refunded and will lease the same to the incorporating unit or units for a period not to exceed 50 years from the date of issuance of the refunding bonds. Any incorporating unit or units to which the property is leased, may sublease the property or any part of the property to any 1 or more persons, firms, or corporations or may contract for the use of the property or any part of the property by any 1 or more persons, firms, or corporations, where the sublease or contract benefits and serves a legitimate public purpose of the incorporating unit or units. Any sublease or contract may extend for a period not to exceed 50 years and is not a franchise or grant within the meaning of any statutory or charter provision. The acquisition of any building or buildings, automobile parking lots or structures, recreational facilities, stadiums, and the necessary site or sites for the property, together with appurtenant properties and facilities by any authority and the contracting for the lease of that property by any incorporating unit or units, constitutes a benefit to and a legitimate public purpose of the authority and the incorporating unit or units. Where any stadium with appurtenant properties and facilities is acquired by an authority and leased to any incorporating unit or units, for the purpose of providing facilities for sports, recreational, and other activities and events, with or without admission charges, and furnishing facilities for use or enjoyment by the public and to induce sports and entertainment organizations, whether amateur or professional, to utilize the facilities for games, contests, and other performances and attractions, the subleasing of the property to, or the contracting for the use of the property by, any sports, entertainment, or similar organization or by any owner of a franchise in any professional sports or athletic league or association, in consideration of the agreement of the organization or owner and, if necessary, the league or association to hold, conduct, or produce games, contests, and other performances and attractions in the stadium, with or without admission charges, constitutes a benefit to a legitimate public purpose of the incorporating unit or units.