305.609.  Dwelling costs — eligibility — payment amount. — 1.  In addition to amounts otherwise authorized by sections 305.600 to 305.630, the head of a displacing agency shall make a payment to or for any displaced person displaced from any dwelling not eligible to receive a payment under section 305.606 which dwelling was actually and lawfully occupied by such displaced person for not less than ninety days immediately prior to:

  (1)  The initiation of negotiations for acquisition of such dwelling; or

  (2)  In any case in which displacement is not a direct result of acquisition, such other event as the head of the United States Department of Transportation shall prescribe.  Such payment shall consist of the amount necessary to enable such person to lease or rent for a period not to exceed forty-two months, a comparable replacement dwelling, but not to exceed five thousand two hundred fifty dollars.  At the discretion of the head of the displacing agency, a payment under this subsection may be made in periodic installments.  Computation of a payment under this subdivision to a low-income displaced person for a comparable replacement dwelling shall take into account such person's income.

  2.  Any person eligible for a payment under subsection 1 of this section may elect to apply such payment to a down payment on, and other incidental expenses pursuant to, the purchase of a decent, safe and sanitary replacement dwelling.  Any such person may, at the discretion of the head of the displacing agency, be eligible under this subsection for the maximum payment allowed under subsection 1 of this section, except that, in the case of a displaced homeowner who has owned and occupied the displacement dwelling for at least ninety days but not more than one hundred eighty days immediately prior to the initiation of negotiations for the acquisition of such dwelling, such payment shall not exceed the payment such person would otherwise have received under section 305.606 had the person owned and occupied the displacement dwelling one hundred eighty days immediately prior to the initiation of such negotiations.