Any public power district or public power and irrigation district may sell to any public power district, public power and irrigation district, irrigation district, city or village, any power plant, electric generating plant, electric distribution system, or any parts thereof, for such sums and upon such terms as the board of directors of such public power district or public power and irrigation district may deem fair and reasonable. As a part of an agreement establishing retail service areas pursuant to section 70-1002, a district may transfer distribution facilities having a rating of less than fifteen thousand volts to a nonprofit rural electric membership corporation in exchange for similar facilities transferred to the district by the membership corporation with a net cash differential to be paid by either party not to exceed ten thousand dollars in any one transaction, but this restriction shall not apply to a sale, transfer or lease of property to a nonprofit electric cooperative corporation engaged in the retail distribution of electric energy in established service areas and which cooperative corporations are organized under the laws of the State of Nebraska or domesticated in the State of Nebraska; Provided, that such property so acquired by a nonprofit electric cooperative corporation shall never become the property or come under the control of any person, firm, or corporation engaged in the business of generating, transmitting or distributing electricity for profit.