New mortgage loans that the Administration purchases shall be loans to: families of limited income; sponsors of community development projects; or homeowners: with primary residences located in sustainable communities; who refinance a residential mortgage loan made by the Department or Administration; or who use the loan proceeds to: purchase the homeowner’s primary residence and make payments on the homeowner’s student loan debt; or purchase the homeowner’s primary residence in conjunction with the homeowner obtaining separate financial assistance from the Administration for making payments on the homeowner’s student loan debt. A commitment that the Administration makes to purchase new mortgage loans shall specify: the interest rate on loans eligible for purchase, which may not exceed the prevailing interest rate on comparable mortgage loans available in the State, independent of public assistance or purchase; and the numbers or volumes of loans under the commitment to be made in specific geographic areas. For any residential mortgage loans to be used to acquire homes for families of limited income, the commitment shall be limited to loans of a specified amount per dwelling unit, based on the current average sale price of new homes in the area, as determined by the Administration. A commitment that the Administration makes to purchase existing mortgages shall require that the proceeds of the purchase be: reinvested, within specified time limits, in new mortgage loans to: families of limited income; or sponsors of community development projects; or invested in short-term obligations pending the purchase or making of the mortgages.