(a) A municipality may not adopt a requirement in any form, including through an ordinance or regulation or as a condition for granting a building permit, that establishes a maximum sales price for a privately produced housing unit or residential building lot.
(b) This section does not affect any authority of a municipality to:
(1) create or implement an incentive, contract commitment, density bonus, or other voluntary program designed to increase the supply of moderate or lower-cost housing units; or
(2) adopt a requirement applicable to an area served under the provisions of Chapter 373A, Local Government Code, which authorizes homestead preservation districts, if such chapter is created by an act of the legislature.

(c) This section does not apply to a requirement adopted by a municipality for an area as a part of a development agreement entered into before September 1, 2005.
(d) This section does not apply to property that is part of an urban land bank program.