; (2) by striking subsection (b) and inserting the following: (b) Increasing government share (1) In general Except as provided in paragraph (2) or (3), the amount stated in an offer as the maximum amount the Government will pay may not be increased when the offer has been accepted in writing. (2) Exception For a project receiving assistance under a grant approved under this chapter or chapter 475, the amount may be increased— (A) for an airport development project, by not more than 15 percent; and (B) to acquire an interest in land for an airport (except a primary airport), based on creditable appraisals at the time of the acquisition or a court award in a condemnation proceeding, by not more than the greater of— (i) 15 percent; or (ii) 25 percent of the total increase in allowable project costs attributable to acquiring an interest in land. (3) Price adjustment provisions (A) In general The Secretary may incorporate a provision in a project grant agreement under which the Secretary agrees to pay more than the maximum amount otherwise specified in the agreement if the Secretary finds that commodity or labor prices have increased since the agreement was made. (B) Decrease in costs A provision incorporated in a project grant agreement under this paragraph shall ensure that the Secretary realizes any financial benefit associated with a decrease in material or labor costs for the project. ; (3) by striking subsection (c)