High housing prices, which long ago slammed the door on low- and moderate-income families in Montgomery County, now threaten to exclude the children of affluent families as well -- pricing them out of the neighborhoods where they grew up and where their roots are.

For many of these children of Montgomery County, now in their 20s and 30s and accustomed to the comfort of living in one of the nation's wealthiest areas, growing up has brought the bad news that they cannot afford to live in their home towns, where the average cost of a new house is more than $125,000.

The three children of Maryland State Sen. Sidney Kramer, for instance, have scattered to Columbia and Greenbelt -- not the ends of the earth to be sure, but not Montgomery County, where they "desperately wanted to live," according to their father. They could not afford it, he said.

Montgomery County State's Attorney Andrew Sonner expects the same will be true of his six children. Sonner moved to the county when he was 8 years old and grew up there. He remembers when deer roamed within a few miles of the county courthouse.

When he came of age, Sonner said, he "never even thought about living anywhere but Montgomery County." But now, he says, his own house in Rockville has appreciated in value so much that he could not afford to buy it himself at today's prices, and his children could not even consider it.

There are those who think that a tear shed for the poor little rich kids is a tear wasted and who argue that the problem is not real.

"I don't see a shortage of medium-priced housing," said Thomas O'Halloran, executive vice president of County Federal Savings and Loan Association in Rockville. The problem is "they want these houses built in Potomac next door to their fathers' and mothers' houses."

Others say that Montgomery County parents helped create the top dollar real estate prices that their children now confront.

"I really don't think they were looking for something grander," Kramer said of his children. "I think they were willing to make the same concessions I was willing to make when I was young, but the choices were not available." All three bought small town houses, he said.

What moderate housing there is falls far short of the demand, according to Kramer and others. Across the nation, the baby boom generation coming of age and the unexpected phenomenon of the two career family created an unanticipated demand for housing that has contributed to rising prices.

"Unless someone can afford their first house to be $90,000, there is just no way to buy in Montgomery County," said Ed Crowley, president of the county's Chamber of Commerce. Crowley works for Kettler Brothers, a major housing developer in the county.

"The average cost of a new, single-family house in the country is $126,000," he said. Prices of older houses average in the high $90,000s for detached homes and in the $70,000 for town houses, he said.

The average listed price of all types of single family, detached houses in Prince George's County in August was $59,500, according to the Board of Realtors there. Prices in Frederick and Howard counties, where many of Montgomery's young house-hunters have turned, generally are even lower.

"That's telling you that you've got to have a whole bunch of bucks to live here or buy your first house," Crowley said in discussing Montgomery County. The house Crowley and his wife bought in 1966 for $26,000 -- "a perfect starter house, almost like a cottage" -- sold two years ago for $96,500, he said.

A 1978 study on "affording the single-family home" by the United States League of Savings Associations, generally disputed the notion that housing was growing beyond the reach of young, first-time home buyers. Such people are able to buy smaller or older houses, use two incomes or go more deeply into debt than is traditional in order to purchase a home, the study said.

The study cautioned that "the potential home buyer can only adjust to relatively higher home prices to a limited extent . . . this cutoff point already is being reached with respect to home buyers in some of our nation's larger, higher-cost cities, and particularly with respect to young, first-time home buyers." The Washington area is one of those areas, the study said.

"On a teacher's salary, I've just got to move out," said Gene Klopf, an elementary school teacher in Howard County. Klopf, 26, moved to Montgomery County with his parents when he was 8.Now he and his wife, who is also a teacher, rent a home in Frederick and expect to buy a house there.

"I'm going to play racquetball this week, and I'm driving down to Silver Spring because that's where my friends are. Everybody is," he said. "That makes it hard, but I don't even question it anymore, because I can't buy anything in Montgomery County."

Not everyone who grew up in the county and cannot afford high prices is forced to move. Some qualify to buying housing built under the county's "moderately priced dwelling unit" program. Others are able to snatch up the few moderately priced houses that come on the market in other ways. Still others buy condominiums.

Some young people are able to stay in the county because their parents can afford to subsidize them.

"We see that a lot, where they're buying $60,000 to $80,000 town houses, but their daddy is gifting them with the down payment, or something, to make it possible," said Crowley.

Camilla McRory, a 25-year-old attorney married to another attorney, is the beneficiary of a low-interest mortgage from her parents that helped buy a house in Sandy Spring.McRory grew up in Sandy Spring; her husband grew up in Bethesda, and both wanted to remain in the county. "What we could comfortably afford to spend would only buy a town house somewhere," she said. "How could we possibly justify spending that much money and only have a town house?"

McRory's mother, Peg McRory, works for the Montgomery County Council and has been active in efforts to make housing in the county available to low- and moderate-income families.

She thought her help was worthwhile, she said, because "if everybody moves and no one has a stake in the community where they live, you've lost part of the stabilizing force that holds society together.