Any such compact as hereinbefore provided may include or provide the method and procedure for establishing by orders of any authority or commission created thereby, among other things, formula prices, equalization of producer prices, assessment of administrative expense against handlers, and compensation for services to producers. Such compact shall be applicable only to that milk which constitutes the regular and the necessary reserve supply for New York City, and the counties of Westchester, Suffolk and Nassau in the State of New York. Any such compact shall provide that in fixing prices for milk, consideration shall be given to all the elements of the cost of production, and other economic conditions which affect the market supply, and demand for milk and its products, and shall provide for the fixing of such prices as will reflect such factors, insure a sufficient supply of pure and wholesome milk and be in the public interest. Any such compact shall provide that any order issued thereunder shall fix a price of any milk covered by such order and distributed in Pennsylvania as fluid milk or cream, which shall be commensurate with the prices established by law on other milk produced in Pennsylvania, and distributed in the same market in Pennsylvania as milk or cream, and not covered by such compact order. Such compact shall also provide that any milk delivered by producers for resale or processing as milk or cream in the city of New York, or the counties of Westchester, Suffolk or Nassau in the State of New York, and diverted from those markets to any market in Pennsylvania, shall be priced at a price commensurate with the prices legally established by the authorized authorities of the Commonwealth of Pennsylvania for the area and market to which such milk or cream is so diverted and sold.