(a) This section does not apply to rates established under Chapter 103, Utilities Code, or Subchapter C or G, Chapter 104, of that code.
(b) The commission may use a cost-of-service method or a market-based rate method in setting a rate in a formal rate proceeding.
(c) On the filing of a complaint by a shipper or seller of natural gas, the commission may set a transportation or gathering rate in a formal rate proceeding if the commission determines that the rate is necessary to remedy unreasonable discrimination in the provision of transportation or gathering services. The commission may set a rate regardless of whether the transporter or gatherer is classified as a utility by other law.