Notwithstanding the restriction on the operation of indefinite price escalator clauses imposed by Kan. Stat. Ann. § 55-1404, after March 1, 1979, such indefinite price escalator clauses in gas purchase contracts subject to this act may be given effect in accordance with their terms to the extent that the price payable under such contracts is not increased above the maximum price such gas would receive if it qualified under section 109(b) of the natural gas policy act of 1978. The maximum price shall be calculated on a monthly basis. Nothing in this section shall be construed to apply to gas produced from new wells, new reservoirs or stripper wells as defined by this act.