BOSTON — It's graduation season, time for college seniors to celebrate good friends and hard work — and the end of those ever-rising tuition payments.

But financial freedom may have to wait a week or two. From cap and gown rentals to printed announcements to jacked-up hotel prices, pomp and circumstance doesn't come cheap these days. Some schools even charge explicit graduation fees of up to $160. While the joy of the moment often means families and students happily fork over the money, graduation weekend can wallop the wallet one last time.

"All this stuff together, it's definitely surprising that after four years of paying $40,000 a year," said Matt Stout, a Boston University senior from East Haven, Conn., "I'm going to spend hundreds of dollars just to get out of here."

His mother, Annie McGuire, a social worker and waitress, has been setting aside money in her credit union account since December to cover the hotel and other expenses for commencement weekend. "It's well worth it," she said.

Still, multiply one family's graduation expenses — roughly $1,100 in Stout's case — by the hundreds of thousands of students graduating from college in the coming weeks, and you've got one very big business. Call it the instant nostalgia industry, and graduation season is its Christmas.

It's hard to say how much Americans spend on the full range of graduation expenses — from bric-a-brac to travel and meals — but it's ample. Class rings seem to be rebounding from an unfashionable period, and despite e-mail, written announcements are surprisingly resilient, especially in the South. The parent company of Jostens, one of the biggest sellers of rings, yearbooks and diploma frames, reported sales of $425 million last year in its scholastic business (though the company doesn't break out separate figures for high schools and colleges).

Stout could be spending a lot more. The BU bookstore's most basic package for the cap and gown, with regalia plus 10 generic announcements, goes for $75 ($10 more if picked up after May 1). The "premiere master package," including 25 personalized announcements and a diploma frame, would cost $265. Lucky he's not getting a doctorate — buying that gown runs $600.

Stout's also passing on the class ring ($311 to $545), yearbook ($70), river cruise ($5) and buffet dinner ($25).

"There will be a lot of great memories, but I don't need to buy hundreds of dollars worth of stuff to help me remember," he said.

A journalism major, Stout might spring for a diploma frame ($145-$209) if he lands a job, but that hasn't happened yet. His housemate, Nando Trindade (who does have a job) bought one only after his parents said they would pay for it. "I don't think my mom really liked the price of it, but my dad said it'll be nice to have a nice little fancy memento," he said.

Caps and gowns are the one expense students generally can't avoid, at least if they want to march in commencement. Nationwide, about half of colleges rent caps and gowns to students, while half sell them, according preliminary results of a membership survey by the North American Association of Commencement Officers. Because of the recollection and cleaning costs with rentals, prices generally end up comparable — between $13 to $65, the group said.

Ultimately, few parents begrudge money spent on such a happy occasion.

Maria Rodriguez of San Francisco has been setting money aside for four years to pay for a trip to celebrate her daughter's upcoming graduation from Smith College in Massachusetts. She'll fly east with her husband, son, mother, brother, two sisters and assorted other relatives from the western U.S. and Mexico.

The graduation trip, plus a few days sightseeing, "is probably going to cost us close to $10,000," said Rodgiguez. "But it's worth it because she's worked very very hard and I want her to feel that we're with her and that we appreciate everything that she's done," she said.

Erika said her mom even splurged for the class ring as a 21st birthday gift.

"She likes to spoil me," Erika said.