Section 24-414. Power to purchase subways, property and contracts of such company

The mayor, in his or her discretion, may purchase  the  subways  constructed  by  such company, and the contracts and other property held
  or owned by it for any of the purposes of its incorporation, for and  in
  the  name  of  the  city. The purchase price shall not exceed the actual
  cost of the property, with ten per cent added to such cost, as may be or
  may have been agreed upon between such company and the  commissioner  of
  general  services. The payment therefor shall be made within four months
  after the delivery to the comptroller of good and  sufficient  and  duly
  executed  instruments  of  conveyance  or transfer to the city, subject,
  however, to any valid liens outstanding thereon, not exceeding fifty per
  cent of the actual cost of such subways, and  subject  to  all  existing
  leases or contracts for the use of such subways.