Section 1590-G. Construction and purchase contracts

The authority shall let
  contracts  for  construction  or  the purchase of supplies, materials or
  equipment in the same manner, so far as practicable, as is  provided  by
  law  for  contracts of the city, except that where the estimated expense
  of a contract does not exceed twenty-five hundred dollars, such contract
  may be entered into without public letting.   Nothing  in  this  section
  shall  be  construed  to  limit  the  power  of  the authority to do any
  construction directly by the  officers,  agents  and  employees  of  the
  authority.