The Commission shall proceed to secure appraisals of all property at the community which is to be sold pursuant to this chapter. The appraisals shall be made by the Secretary of Housing and Urban Development or his designee. The Secretary of Housing and Urban Development shall be reimbursed from the Community Disposal Operations Fund for the cost of such appraisals. Appraisals made under this section shall be the appraisals on which the Secretary of Housing and Urban Development may insure any mortgage or loan under the National Housing Act [12 U.S.C. 1701 et seq.] until such time as he finds that the appraisal values generally in the community no longer represent the fair market values of the properties.