When 90,000 fans crowd into Ben Hill Griffin Stadium on the University of Florida campus, it is more than just a football game. It is a rollicking, emotional, transcendent experience. A very big deal, in other words.

But increasingly, that experience comes with a hefty and controversial price tag.

These days it takes more than a ticket to get into the stadium. Florida and scores of other football powerhouses require fans to make thousands of dollars in “donations” to their athletic departments before they even get a season ticket. The level of donation determines where fans sit. The more they give, the better the view. A seat in the prized Bull Gator section at Florida requires a $14,500 contribution.

Don’t think there isn’t a waiting line. Demand for football tickets almost always exceeds supply. In recent years, a new fan hoping to buy a season ticket to Florida games had to write Gator Boosters Inc., Florida’s non-profit booster club, a check for $1,800. That was the entry-level donation and does not include the cost of the ticket, which is hundreds of dollars more. To inch up the waiting line, Florida officials recommend boosting contributions even higher.

The money adds up. Last year, Florida took in $17.5 million from its ticket contribution scheme, records show. Including luxury suites and other premium seats, the figure swells to nearly $35 million, equal to about one-third of the entire athletic budget. And that’s only one school.

Nearly every major football program — from South Carolina to Texas to the University of Southern California — now requires its fans to make an annual “contribution” to get a season ticket. In the mid-1980s, a congressional panel estimated ticket schemes raised $100 million annually. Today, that figure is closer to $500 million, interviews and records suggest.

Nearly all of the money is untaxed, part of a long, controversial history of tax breaks Congress has awarded to big-time college football even as the sport becomes more and more commercialized. Critics like John D. Colombo, a law professor and tax expert at the University of Illinois, say the tax breaks defy the laws of charity and highlight how Congress has carved up the tax code benefitting scores of special interests.

“The easy and direct answer is that it’s not charity,” Colombo said. “If you receive a quid pro quo, that is, something tangible, it’s considered not to be a donation. The IRS has held that position forever. And it has been upheld by the courts. But Congress decided to act on its own and call the payments charitable contributions.”

Schools have different names for their mandatory ticket schemes, which mimic “personal seat licenses” used by professional teams. Some call them “premium seating programs.” Others call them “priority seating plans.” The University of California, Berkeley, calls its new plan an “endowment seating program.” Boosters who give $225,000 are able to guarantee themselves a seat at Cal football games for the next 50 years.

The purpose of the ticket schemes is to generate more revenue by taking advantage of the unprecedented demand for seats. Cal’s new seating plan has raised nearly $41 million in cash so far, according to university financial statements, with tens of millions more expected. The Southeastern Conference, which includes Florida, annually collects more than $100 million in seat donations, records show. At Louisiana State University, a perennial football power, contributions have more than doubled since 2005 — to $22.2 million annually, according to a state audit.