Tickets to get into the Barnes Foundation gallery on the Benjamin Franklin Parkway are pricey, $25 for adults.

But a few days ago, a reader called and asked when the Barnes had raised its price to $30.

Good question.

Welcome to exhibition-oriented dynamic pricing: Museum prices rise and fall depending on what there is to see, time of day, and other marketing variables.

At $30, it costs more to enter the Barnes than any other art museum in the country, according to a list compiled by Art News since the decision by the Metropolitan Museum in New York to end pay-what-you-wish ticket prices for out-of-state visitors. The Met now charges $25.

But wait. That $30 Barnes ticket is not the "official" admission price — even though  you can't get in without paying it. Barnes officials say the $30 is only temporary: $5 is added to every adult ticket sold during "Kiefer Rodin," a special exhibition that runs through March 12. After that show closes, the price falls back to $25 – at least for a time.

When the next special exhibition, "Renoir: Father and Son/Painting and Cinema," opens May 6, the price will rise again. Ditto with "Berthe Morisot: Woman Impressionist," opening Oct. 21.

"Since this isn't a new policy, we didn't issue a press release" about the price increase for "Kiefer Rodin," said a Barnes spokeswoman. "We make pricing information available on our website, as well as widely promoting our free first-Sunday programs and other free and discounted offerings."

First-year Penn medical students sharpening their observation skills at the Philadelphia Museum of Art.
TOM GRALISH / Staff Photographer
First-year Penn medical students sharpening their observation skills at the Philadelphia Museum of Art.

What do other institutions do? At the Pennsylvania Academy of the Fine Arts, the charge for a single adult ticket is a straightforward $15. "We don't ever bump up our admissions price," a spokeswoman said.

The Museum of the American Revolution charges $19 for adults, unless it charges $25. The lower price requires visitors to set a time and day for their visit. The museum website notes, however, that the ticket will be good  "at any time after the time you selected. On all but our busiest days, we are happy to honor your ticket at any time on the date you selected."

The higher-priced ticket allows access at any time. A distinction without a difference? The museum doesn't think so. "Some days are completely booked," a spokeswoman said. That additional $6 will get you in.

The Philadelphia Museum of Art has a straight admission charge of $20 for adults and a pay-what-you-wish policy every Wednesday after 5 p.m. and on the first Sunday of every month. But that does change on occasion.

"The vast majority of our exhibitions are included with general admission," said a museum spokeswoman. "When we have ticketed special exhibitions, they have been priced at $25 and include general admission.  At present, we do not plan to impose a special exhibition surcharge for the next couple of years."

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“Terracotta Warriors of the First Emperor,” at the Franklin Institute through March.
Courtesy of The Franklin Institute
“Terracotta Warriors of the First Emperor,” at the Franklin Institute through March.

And then there is the Franklin Institute. Prospective visitors are advised to take along a calculator to determine prices.

The general admission adult ticket for the institute is a straightforward $23. But if you want to see a special exhibition, like "Terracotta Warriors of the First Emperor," on view through March 4, it'll cost you $35 total if you want to go before 5 p.m. After 5, when the rest of the museum is closed, you can see the warriors for $20.

Tack on $6 if you want to go to the IMAX Theater or the Franklin 3D Theater. If you want to go only to the theaters, it's $10, although the IMAX ticket price varies "for major motion features," according to the website.

Want to do the SkyBike? That's another $3. The Blue Angels Adventure Flight Simulator will cost you  $5 more, the same as Max Ride.

The institute's newish Escape Rooms, which operate on their own schedules and are designed for groups, cost $28 for a single ticket, $399 for groups.

A spokeswoman for the institute acknowledged multiple variables in pricing.

"It's so like not a standard," she said. "There are so many exceptions. It's a challenge."