High-level members of President Reagan's team and newly seated Republican members of Congress have had to face the unreal world of Washington's real estate values.

The newcomers do not seem to have a huge impact on a market in the doldrums because of high prices and interest rates, but at least have inspired hope in some idle real estate agents.

Here's where some politically oriented Washingtonian's, both old and new, are now living:

Secretary of State Alexander M. Haig recently purchased a new Georgian colonial for an undisclosed figure on Cape Cod Court NW in Westmoreland Hills, (where Harvey Borkin's Douglass Construction Co. is building 12 over-$400,000 houses on a site off Massachusetts Avenue.) The Haig house has four bedrooms and six fireplaces.

Agriculture Secretary John Block bought a house for $317,000 on Palisades Lane NW, in the Briarcliff subdivision. The house had been owned by former assistant secretary of state Warren Christopher whose name became so familiar during the hostage crisis last year.

Defense Secretary Caspar Weinberger is reported to have purchased a dwelling for an undisclosed sum in the Kalorama section of Northwest Washington.

Treasury Secretary Donald T. Regan for several years has owned a home in the prestigious Mount Vernon area near the Potomac south of Alexandria.

Secretary of Health and Human Services Richard Schweiker, who formerly served in the Senate from Pennsylvania, already owns a house in the Swinks Mill Road area of McLean.

At the Department of Housing and Urban Development, an aide said that Secretary Samuel R. Pierce has rented a co-op apartment in the District.

HUD Undersecretary Donald I. Hovde, a recent president of the National Association of Realtors, still is staying in the L'Enfant Plaza Hotel but is looking hard for a house in Northern Virginia. "The house prices here are really something," said the man whose background should have prepared him for Washington's housing-price traumas. The Hovdes plan to keep their house in Madison, Wis.

Office of Management and Budget chief David Stockman, whose name has achieved a high recognition level in recent weeks, reportedly rents an apartment in Northwest.

Top White House Aide Erwin Meese III and his wife recently bought a two-stroy colonial in the Cedars of McLean for $256,000. (The house is near the home of Zbigniew Brezezinski, former top national security adviser in the Carter administration.)

James Baker -- Reagan's other top aide -- and his wife have purchased a large house on Foxhall Road, NW, reportedly for $750,000.

Reagan press secretary James Brady and his wife have owned a modest house in north Arlington for several years.

Nancy Reagan's chief of staff Peter McCoy is said to have bought a Northwest house for more than $400,000. The house once was occupied by former Enery secretary Charles Duncan and prior to that by George Bush.

Presidential assistant Michael Deaver and his family have rented a house on Dexter Street NW, just off Foxhall Road. The Deavers own a home in California.

Sen. Arlen Specter (R-Pa.) from Philadelphia has bought a three-bedroom condominium at James Place NW in Georgetown, where prices range from $152,900 to $369,500.

Sen. Slade Gorton (R-Wash.) has bought a Capital Hill town house "with a large mortgage," said an aide, who observed that prices here are "appalling." The Gortons also have a home in Olympia, Wash.

Sen. Don Nickles (R-Okla.) and his wife have bought an over-$100,000 house in the Vienna area.

Sen. Jake Garn (R-Utah), a second-termer now heads the powerful Banking, Housing and Urban Affairs Committee, owns a single-family house in McLean and another in Salt Lake City.

Sen. Dan Quayle (r-Ind.) already owns a house in McLean that he bought while serving in the House and Sen. James Abdnor (R-S.D.), who also moved up from the House, owns a house in Falls Church.

Sen. Charles Grassley (R-Iowa), who also had served in the House, and his family have a split-level in the Mount Vernon area and a farm near Waterloo, Iowa.

Sen. Warren Rudman (R-N.H.) has rented an apartment on Capitol Hill, 1 1/2 blocks from his office; in Nashua, N.H., the Rudman family owns its own home. Sen. John East (R-N.C.) is renting a condo apartment in the high-rise Alexandria House; the Easts also have a home in Greenville, N.C. Sen. Alfonso D'Amato (R-N.Y.) has rented an apartment in Crystal City near National Airport, from which he will commute to his family home on Long Island.

Sen. Mack Mattingley (R-Ga.) is a tenant in Georgetown. Rep. John LeBoutiller (R-N..) rents an apartment on Capitol Hill.

The Senate is represented in the Watergate co-op apartment complex by renters such as Alabama's Jeremiah Denton, Florida's Paula Hawkins and North Dakota's Mark Andrews.

Denton's office said he's there only temporarily because he has made a deal to rent another apartment in the District, off Connecticut Avenue NW, for his wife and family. Back in Mobile, Ala., they have a large house on the Fowl River.

Hawkins, her engineer husband and their children own a home in Winter Park, Fla. Andrews and his wife own a farm in the Red River Valley.

New members of the House include Virginia Republican Stan Parrish, who lives near the Potomac River in Woodbridge, and Republican Frank Wolf, who lives outside Vienna.

Rep. Roy Dyson, a Maryland Republican whose far-flung district includes part of southern Maryland and some of the Eastern Shore, said he commutes daily from his farm in St. Mary's County near the Patuxent Naval Base.