How are people in this area able to become buyers in one of the most expensive new house markets in our land?

Eleven individuals and couples who intend to purchase house costing $125,000 and up in the new Langley Oaks subdivision of McLean were asked how they are doing it. The buyers, (who asked not to be named), had put down $1,000 deposits on houses Centex Homes of Washington plans to begin building soon on a tract of wooded land inside the Beltway near Langley High School.

They gathered for a "meet your neighbor" reception at the National Housing Center, headquarters of the National Association of Home Builders.

Most of the Langley Oaks buyers already own houses. They have considerable equity in those houses, which they say have appreciated in value enough to help them move up to a more expensive home. Many said they were attracted by the McLean location. A number were already living in the sought-after section of Northern Virginia that fans out from the Central Intelligence Agency headquarters near the Potomac River.

Here are some of the buyers:

A Navy catain, 43, and his wife and one child currently live in a McLean house in the $90,000 range. This will be their seventh house purchase. "It's a combination of upward mobility and a set of priorities that enables us to be satisfied with two cars that are six and seven years old," the captain said.

Another couple in their 40s, with two children in college, also lives in a $90,000 McLean house, which has a small morgage left to be paid off. The wife sells real estate and they own other property. It will not strap them to buy the new house, they said.

Another young couple, with children aged three and six, has been in an older house in the same relative price range for seven years and has good equity. This government official and his non-working wife plan to move because of "better location." It will be to financial strain.

Another couple with two children said the McLean house would be their third and indicated that they are making a lateral move financially. He's inremodeling and renovation in D.C. They've lived in the McLean area eight years and could afford an even more expensive house. "We're equity-rich," he said.

Another McLean couple with grown children is buying a house of approximately the same value "because of growth potential." He's a fiftyish real estate broker.

A Navy officer who has owned a McLean house since 1966 is moving because he wants more house to accommodate in-laws who will live in. He's moving up from the $90,000 reange but said it is no financial problem because of equity and a good nest egg. "$125,000 is nothing in McLean," he added.

A real estate broker is planning to buy in Langley Oaks because she already lives in the area and likes the locatrion. She will be "trading down" from a larger house in the $200,000 range.

A Springfield, Va., attorney, 34, with a working wife and two children is planning to move up from a $75,000 house. "We're depending on appreciation in the new house and we like the location. We had not planned to move for a while," he said.

A trial attorney, 35, now lives in his first house in McLean, valued at about $75,000. He said he is banking on income potential, attractive interest rates and the fact that a house "is the best available investment today."

A GS-16-ranked government employee, his wife and three children have lived in a $90,000 McLean house for three years. Their equity and the better break on tax deductions with the new house and a larger mortgage are motivations. "This will be our third house and we've done all right on all of them . . . " he said. Their first, in New Jersey, was purchased with an $800 down payment, he added.

A government management administrator and his wife, who also works, have one child. At ages 33 and 29, this will be their fifth house. They have retained two houses as investments, but point out that they have no "fancy cars."

"Preselling" at the Langley Oaks subdivision, where the developer operates out of a trailer and model homes are just going up, has been exceptionally strong. Some 90 houses are expected to be built in the 308-lot project in the first year.