But who says that they didn't actually request $1.5M in used bills after doing the math of what it would take to make a cube. Or fill it up with $1M in used bills, and come back and make another request for $500k that also got approved...
I have a friend who works at a firm which specializes in engineering and constructing exhibits for museums and all kinds of public spaces. There's a whole industry ecosystem around doing this. They get brought in on contracts by design firms which specialize in permanent installation exhibits who get hired by the person responsible for exhibits at a museum or exhibit space. It's no different than most niche specialty industries. Even though it's comparatively small, there are still thousands of sites and hundreds of firms. People who do this specialize in it, develop long-term careers and have resumes they care about. Jobs for firms and people come by reputation and word of mouth. Delivering on time, on spec and on budget is crucial for survival. The facilities manager for this Fed building hired an exhibit space manager who developed a budget for this public tour project and then put it out to exhibit design firms for bids. The project was approved on a fixed budget and time frame. The overall budget the exhibit space manager submitted to the facilities manager certainly included the cost of the cash in the cube.
But the bigger reason no one was cavalier about just filling it up with $100 bills is that this exhibit is different because the exhibited artifact is of uniquely high-value (and unlike a Rembrandt, immediately spendable), so it probably had to have a security assessment and is very likely insured against loss (not just theft but fire/water damage etc). The cost of insuring and securing the exhibit was calculated before the budget was ever approved. Adding another 50% in cash would increase the insurance premium.
An engineer or artist that reliably find ways to go 50% over budget and generate contract extensions is a highly sought professional amongst vendors that specialize in the public sector.
In gov work contract extensions are almost guaranteed, provided your company also have the civic spirit of contributing to our democracy with health campaign donations.
> "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.
So it seems very likely to me that whatever money is in the cube is decommissioned.
As a side note: In some countries, central bank employees are the only individuals that can actually hold non-paper M0 (or MB?) money, since they get paid their salaries into a central bank account, which are otherwise only available to commercial banks. This used to be the case in Germany and Austria, but has been phased out at some point, as far as I remember.
But even if Fed employees just get paid in regular old M1 demand deposits, that's money nonetheless.
https://hrreview.co.uk/hr-news/strategy-news/bank-england-cl...