A family or individual qualifies as a family of limited income if the income of the family or individual does not exceed the upper income limit that the Secretary establishes. Factors that the Secretary shall consider in setting the upper income limit under subsection (a) of this section include: the total amount of family or individual income deemed available for housing; the size of the family; the ability of the family or individual to compete successfully in the private housing market; the cost and condition of available housing; and standards and definitions under related federal and State housing programs.