Sad news for all you label-conscious bargain hunters on Rockville Pike: Saks Off 5th is closing its doors after a three-year run at Congressional Plaza. The Rockville location is a victim of cost-cutting at Saks’ parent company, Hudson Bay Co., which also is closing some of its Lord & Taylor stores. The Congressional Plaza Saks store will be open until October, with discounts getting deeper as the months go by.