Subtitle D, Title 10, does not apply to a purchase or lease under this chapter. The executive director, as appropriate, may approve in writing the purchase or lease of goods and services needed to repair or improve an area within the Capitol, Capitol extension, Capitol grounds, or General Land Office building, if the cost of the purchase or lease will not exceed $50,000. The executive director shall notify the board in writing of any expenditures in excess of $50,000 made under this chapter.