Yet a small but growing number of such parents are abandoning even some of the top-performing public schools in the region. In school districts like Scarsdale, N.Y., and Montclair, N.J., where high test scores and college admission rates have built national reputations and propelled real estate prices upward, these demanding families say they were disappointed by classes that were too crowded, bare-bones arts and sports programs, and an emphasis on standardized testing rather than creative teaching.

Some are private school graduates themselves who, try as they might, feel guilty giving their offspring anything less. Others were spoiled by their children’s experiences in private school in preschool or the early grades before leaving the city. Still others simply found that public school programs in suburbia did not live up to their promise.

So they forsake city living to wind up shouldering the double burden of high taxes and tuition bills. Or they end up moving back to Manhattan or commuting with children in tow to the city’s private schools.

“It was not part of our plan at all, and I’m not sure how sustainable it is,” said Tracy Fauver, of Bedford, N.Y., whose three children attend the Rippowam Cisqua School in the town; tuition there runs from $17,500 to more than $26,000 per student. She said her husband’s Ford Focus had become something of a joke parked alongside his co-workers’ Mercedes-Benzes and BMWs, as the family has forgone fancy cars and vacations to afford the tuition.

Headmasters and admissions officers at more than a dozen prestigious private schools in the region — including Rye Country Day in Westchester, the Lawrenceville School in New Jersey and the Westminster School in Simsbury, Conn. — say they have seen steady increases in applications in recent years. Private-school placement consultants in New York City and Westchester track similar trends: one such company, Manhattan Private School Advisors, now counts 325 suburban families among its clients, more than three times as many as three years ago, while another, Abacus Guide Educational Consulting, gets five calls a week from Westchester families, compared to one a week two years ago.