In the case of any purchase or refinancing under this subsection involving property to be rehabilitated or developed under section 1437 o 1 of title 42, the Secretary may—

(A) include rehabilitation or development costs of not to exceed $20,000 per unit, except that the Secretary may increase such amount by not to exceed 25 per centum for specific properties where cost levels so require;

(B) permit subordinated liens securing up to the full amount of mortgage financing provided by State or local governments or agencies thereof; and

(C) pay such benefits in cash unless the mortgagee submits a written request for debenture payment.