The authority has full charge of the acquisition, construction, and completion of the regional transit terminal or any part thereof authorized by it. The authority may construct the regional transit terminal or any part thereof and acquire all property necessary therefor on such terms and conditions as it deems advisable or may contract with a developer for such work. The authority, without awarding a contract for the construction of the regional transit terminal or any part thereof, may do the work directly and may purchase the materials, hire labor, and do all other things necessary for the doing of the work. When any part of the work is to be done or performed by any department or agency of the United States of America or the State of California or any city, county, district or other public corporation, jointly or in connection with the authority, the portion of the cost thereof to be borne by the authority may be turned over to the department, or agency, or political subdivision or public corporation to be expended by it in the acquisition, construction, or completion of the regional transit terminal or any part thereof.