The next time Congress asks for a pay raise (and it will probably be only a couple of years from now), let's ask them about the House and Senate stationery stores. These shops sell gifts and office supplies to members of Congress and their staffs at huge discounts. And legislators maintain their right to shop there even after leaving office. Gary Hart, for example, was spotted in the Senate store last November doing some Christmas shopping. Spy magazine recently compared prices at the congressional stores with those at a regular stationery shop down the street.