Private high schools are known for their high tuition fees. In fact, tuition fees of the most select private secondary schools rival those of the nation's best universities, such as Harvard, Stanford, Yale, MIT and Princeton. Because private high schools prepare students for elite universities, they are also often referred to as prep schools.
 

Average Tuition Fees

In the 2009-2010 school year, according to the National Association of Independent Schools, or NAIS, the average tuition at day private high schools stood at $19,906 a year, while boarding schools averaged $40,875. The tuition is even higher for the most elite prep schools.

Most Expensive Prep Schools

According to Forbes, the most expensive private high schools in the United States are Middlesex School and Concord Academy in Massachusetts, Lawrenceville School in New Jersey, and Hotchkiss School in Connecticut. All of these schools charge more than $30,000 a year.

Price Dynamics

The tuition at prep schools has been rising much faster than inflation since the 1980s. The Forbes magazine cites NAIS data that tuition fees in 2006 were 79 percent higher than 20 years before, even after being adjusted for inflation. The rising fees reflect the growing wealth of the most well-off parents and their desire to give their children the best education money can buy.

Financial Aid

Not all students at prep schools pay the tuition fees and some receive financial help from the schools. According to NAIS, 10.4 percent of the budget expense, or 11.6 percent of budget income, of day private high schools goes to financial aid for students. The figures for boarding prep schools stand at 15.4 and 19.6 percent, respectively.