2006 New York Code - Total Cost.

 
    § 503. Total cost. No merchant shall offer a rental-purchase agreement
  requiring periodic payments totalling more than an amount, fifty percent
  of  which  equals  the cash price of merchandise. When periodic payments
  made by a consumer total an amount, fifty percent of  which  equals  the
  cash  price  of the merchandise, the consumer shall acquire ownership of
  the merchandise and the rental-purchase agreement shall terminate.