Gillian Spolarich, a high school senior from Silver Spring, chose the College of Charleston over American University even though it was her second choice school, because the Charleston campus offered her a large merit grant. (Gillian Spolarich/COURTESY OF SPOLARICH FAMILY.)

Gillian Spolarich’s college search played out like a romantic triangle. She was set on American University. But the College of Charleston was set on her. The Southern suitor sweetened its admission offer with a pledge of more than $10,000 in merit aid.

In the end, the high school senior from Silver Spring took the better offer from the second-choice school in South Carolina, placing price before prestige.

It is becoming a common scenario post-recession: Affluent applicants, shocked by college sticker prices and leery of debt, are choosing a school not because it is the first choice but because it is the best deal. Students are using their academic credentials to leverage generous merit awards from second- or third-choice schools looking to boost their own academic profiles. Colleges are responding with record sums of merit aid, transforming the admissions process into a polite bidding war.

The average student at a private college last year reaped a 42 percent discount on the published tuition, according to an industry survey, a historic high. Admission experts say more colleges use merit awards to lure strong students who might not otherwise attend, including those who could afford to pay full price.

Private institutions spent $2,060 per student in 2010 on aid to families without financial need. That category of aid has increased by half in 10 years in constant dollars, according to the College Board. Public colleges, too, trade in merit aid: They spent $410 per student on aid “beyond need” in 2010, a 37 percent increase in 10 years.

In addition, experts say, a significant amount of merit aid is given to other students. But the total is hard to quantify.

Price has always been a concern in choosing a college. But experts say there is a tradition among many upper-middle-class families — those with six-figure incomes and little hope for need-based aid — of finding the money to attend the most selective school that offers admission, whatever the price.

That is changing, admissions counselors say. Today, even privileged families are questioning the wisdom of paying $50,000 a year for college, especially on an institution that lacks the pedigree of a Harvard or Yale.

“Even if you have money, $200,000 is still a lot of money,” said Lisa Sohmer, director of college counseling at the private, college preparatory Garden School in Queens, N.Y. “The thing to remember is, there are extraordinary educations to be had at colleges that cost all different kinds of money.”

Spolarich, 18, seemed a natural fit at American. Its Northwest Washington campus is close to her Montgomery County home. Its strong communications program beckoned to the senior, an editor at the Blake High School Beat student newspaper. She was one of many AU applicants representing the top 5 percent of their high school class.

The College of Charleston was a more impulsive choice. Spolarich visited the campus while driving to Florida with her mother, drawn to the colonial charm of Charleston and its 18th-century public college, one of the nation’s oldest.

Spolarich soon learned that, with her 3.85 unweighted grade-point average and 30-plus ACT scores, she was just the sort of student the College of Charleston aspired to attract. Her numbers, unremarkable in the AU applicant pool, stood out at Charleston. AU wanted her. Charleston seemed to want her more.

“They were straightforward at the beginning that if she applied, and if her numbers were what she had written on the [information] card, they would be able to make her a very good offer,” said Audrey Spolarich, Gillian’s mother.

The wooing intensified when Spolarich returned to Charleston in March for Accepted Students Weekend. In the honors college, Gillian would enjoy smaller classes, interdisciplinary study, preferential housing and first dibs on registration. She met the college president.

“It was really crazy how friendly everyone was,” she said.

The college offered her enough aid to lower the total annual bill from about $34,000 to about $21,000, effectively erasing the financial penalty for Gillian as an out-of-state student, Audrey Spolarich said.

AU had offered no aid. Tuition, fees and living expenses total about $50,000 a year, typical for a first-rank private university. The Spolarich family did the math. Even with two solid incomes (Gillian’s father is chief financial officer for a federal agency, and her mother is a strategic development consultant), someone would have to postpone retirement to cover the cost.

“And then, I don’t know, my mom and dad were just like, ‘I can’t pay for this,’ ” Gillian Spolarich said. “And I was like, ‘I know, this is stupid.’ ”

Merit aid, uncommon 30 years ago, has grown into a dominant admissions tool at hundreds of private and public colleges seeking top students.

“They’re looking to improve the profile of the class to give themselves bragging rights,” said Douglas Bennett, president of Earlham College in Indiana.

Of course, colleges also have long steered scholarships to athletes and others with special talents.

Most aid is still need-based. But admission experts say colleges increasingly use grant dollars as a tool to attract good students, needy or not. The full extent of merit aid is hard to gauge because schools define it in different ways, said Haley Chitty, spokesman for the National Association of Student Financial Aid Administrators .

A few dozen of the most selective colleges offer financial assistance only for need, an arrangement they deem more equitable. But then, those schools can attract top students without merit aid, said Amanda Griffith, an economist at Wake Forest University.

Hundreds of other colleges favor merit aid, offering packages that can cover most or all of the cost of an education. Schools manage the expense by passing it along to the students who pay full price. Merit aid is thus partly responsible for the steep tuition increases of the past 20 years.

Spiraling aid has caused financial trouble for some private colleges. For college applicants, on the other hand, it has spawned a buyer’s market. High-achieving students can reap steep discounts at colleges with strong reputations for undergraduate education.

“We’re getting calls back from families saying, ‘We’re getting this much from another college. Can you match it?’ ”said Joseph Urgo, president of St. Mary’s College of Maryland, a public liberal arts college that competes with private institutions.

St. Mary’s charges $25,000 a year in in-state tuition and living expenses, half the price of some competitors. But some of them are willing to bridge the gap by offering tuition discounts of 60 or 70 percent.

“We’re wasting billions of dollars nationally competing for kids,” Urgo said. “But we can’t stop it.”

Some schools package merit awards with admission to elite programs and other perks. This is “another level of merit aid, where you’re not just getting the money, you’re getting the special attention,” said Sally Rubenstone, a senior adviser at the college admissions Web site College Confidential.

Samantha Shevach of Queens chose the public University of Delaware over Penn State, her first choice, because of merit aid.

Shevach was a strong applicant, with an A average at Mary Louis Academy, a Catholic college preparatory, and high SAT scores. She had always wanted to go to Penn State and applied to Delaware as an afterthought.

Penn State offered admission, but not aid. “It was $43,000 a year,” she said. “So expensive, even for a state school.”

Delaware deemed Shevach a top prospect. The school offered $20,000 in merit aid and a spot in the honors program. At an event for admitted students, she met other honors recruits who had turned down Ivy League schools.

Shevach said she chose the Delaware school for the sake of her parents.

“They said that they would have paid for Penn State,” she said. “But I didn’t want them to be $160,000 in debt. You need to think about the investment you’re making: Are you going to get that $160,000 back?”