At any time after the approval of the redevelopment plan and before disposing of any of its lands or properties, the redevelopment agency shall appoint one or more, but not more than three competent persons to make independent appraisals of the value of its property, based upon the future use of the area under the redevelopment plan. The appraisals shall serve only as a guide for the agency in determining a fair price for the disposal of its land and property but need not be adhered to in making the disposal, and shall become a public record and subject to examination by any interested person after the disposal.