Per this site:
https://home.treasury.gov/services/currency-and-coins> "U.S currency is produced by the Bureau of Engraving and Printing and U.S. coins are produced by the U.S. Mint. Both organizations are bureaus of the U.S. Department of the Treasury."
But even if this exhibit was at a U.S. Mint site, your assumption doesn't account for how the real world works. The people involved in planning, creating and operating a public exhibit space like this on behalf of some museum, department or company are just regular employees who report to mid-level managers with careers in facilities management. I'm not an expert but if this was a U.S. Mint site, I'd guess that the bills on display would be technically 'retired' (or whatever term they have for bills that are removed from circulation). Since the Federal Reserve is a quasi-governmental organization, I can't really guess if these bills are similarly retired or simply cash, the time-value of which this exhibit space is carrying on their balance sheet. Either way, based on the way the real world actually works, it's almost certain the cost of this cash is very precisely tracked and accounted for on an audited budget that some mid-level manager is responsible for balancing right alongside the payroll for ticket takers, security guards and janitorial.
