Leffert Lefferts gets up at dawn to ride horses on the Middleburg, Va., estate and then goes to work to manage the horse country office of Previews, a international real estate marketing firm that specializes in expensive properties. His family has been in real estate and construction for four generations. He was introduced to the business as a teen-ager working for the homebuilder father in New Jersey.

"He was a serious, hard-working man who sent me to the job site early in the morning and told me to stay there until he picked me up," Lefferts said. "After doing a day's babor, I was expected to stick around and show the houses to anyone who came by."

That indoctrination didn't dampen the natural ardor of this George Alien look-alike, who later went to prep school in Rhode island, graduated from Columbia University in 1962 and then worked for family-owned concerns and other companies, including the Brooks, Harvey mortgage banking firm in New York City.

Lefferts came in Middleburg two years ago, bought the 500-acre Mount Gordon farm and became vice president . of the new Sotheby Parke Bernet Internation Realty Corp office in the town.

Earlier this year Sotheby move its office to Warrenton and Lefferts switched to Previews, working out of the same office in a 150-year-old brick house on the Middleburg thoroughfare, West Washington Street. Both Sotheby and Previews specialize in unusual, high-priced estates and houses. They compete for the same kind of business but take slightly different approaches to the marketing task.

Lefferts' territory includes West Virginia, Maryland, Delaware, the District and Virginia.

"Our market is relatively small," he said, "because transactions over $250,000 account for only 0.2 percent of all the residential sales made across the land."

Previews' approach is to work for the seller of a property that requires more than local exposure, Bruce Wennerstrom, Preview president, says that about half the company's listings "come through brokers who recognize the value of supplementing their own abilities. Then one is designated the controlling broker. Leads are turned over to that broker and outside brokers are obligated to work through him too."

Wennerstrom, interviewed during a recent visit form corporate headquarters in Greenwich, Conn., said that the other listings come front owners who want a Previews' analysis and marketing program, the latter usually including fancy brochures for distribution to brokers and potential buyers. "We normally appoint a local broker to show the property for us," he said. "We will, if an owner requests, show a property ourselves."

One property currently being marketed by Previews is Quarry Hill, a classy French chateau-type mansion with three acres of lawn and gardens on a hilltop near the Homestead in Hot Springs, Va. It's on the market for $865,000, and has a greenhouse.

Another Previews property is Winter Place Farm, a 222-acre spread north of Salisbury, Md., that features everything a pampered horse might want for gracious living - even chandellers in the indoor riding ring. The listing price is $3.9 million.

Although even Middleburg recently began to feel the gasoline crunch, Lefferts said that's not really a problem.

Charles Sellhelmer, manager of the Sotheby office in Warrenton and formerly associated with Lefferts when Sotheby was in Middleburg, says that the market is simple for both firms. Despite a downturn in the economy, the market for large properties remains more stable than the general residential market, he maintains. Sellhelmer acknowledge the influence of foreign buyers in their market, but say that Americans still predominate.

Anyone thinking seriously about a large or small estate in Loudoun or Frauquier countries can count on paying $1,500 to $10,000 per acre, depending on size. Anything under 25 acres is relatively rare and most big landowners don't seem to be interested in sub-dividing their land.

In the Midleburg milieu, as with arces where many of the Previews' properties are marketed, there is an undentable romance associated with amblence and style.

And mortgage financing, now a deterrent to the middle-range housing market, is "not really a problem with these estates," Lefferts said. CAPTION: Picture, Leffert Lefferts, the new head of the Previews relty office in Middleburg. By Margaret Thomas - The Washington Post