centerline, unless the terms of the initial sale, lease or transfer so provide. The consideration paid for the sale, lease or other transfer of the real property shall be determined by the redevelopment agency, provided, if the cost or carrying charges of such real property to the redevelopment agency are greater than such consideration, the redevelopment agency shall first have specific authorization from the legislative body of the municipality for the sale, lease or other transfer at any lesser consideration, and the municipality may appropriate and authorize the expenditure of money to compensate for any portion of the difference between the acquisition cost of such real property and such sale, lease or other transfer price of such real property at a lesser consideration to a redeveloper, but in no case shall such sale, lease or other transfer price be lower than the use value of such real property. Each contract for sale, lease or other transfer to a redeveloper shall provide, among other things, (a) that the real property transferred shall be developed and used in accordance with the redevelopment plan or such plan as modified with the approval of the redevelopment agency; (b) that the building of the improvements shall begin within a period of time which the redevelopment agency fixes as reasonable; and (c) that all transfers of real property by the redeveloper shall, until the original construction thereon is completed and approved by the redevelopment agency, be subject to the consent of the redevelopment agency; except that the requirements of subdivisions (b) and (c) above may be waived by the redevelopment agency with respect to any bona fide mortgage placed upon the real property by the redeveloper in order to obtain financing for the project. Any such