There's "coin deforming" machines here in the UK too. Most of them that I've seen have notices on them explaining the current state of legality of doing this to coins in the UK (i.e. that it is legal, at least since the "Blah-De-Blah Coins And Currency Act of 19XX, Amendment 3", or whatever it might be). Most of them also have (say) one position[1] for the penny to be deformed into an embossed lozenge as a memento of the museum/whatever and
two for larger coins (I've seen them request to 50p (£0.50) coins!) for the privilege.
(It's usually museums, especially ones that contain mechanical "Victoriana". Some are "pre-decimal penny" presses that rather than being converted to use newer coins (perhaps 2p pieces, being more of the right size) are supplied (sometimes internally, with different modifications) with discs of metal to approximate the old pre-1970s "1d" pieces. For which obviously material costs need to be paid, from amongst the "presumed donation" needed for operating[2] the machines.)
((Actually, I've never actually seen a
modern machine of this kind, so I might be misinterpretting the "Disney"-type machine being described above.))
Anyway, this "costs more money than the face value" outdoes (in proportion) even the Millenium Dome thing, where you could get a special-edition (legal tender, so theoretically spendable) coin for only
twice the face value.
[1] Rather than a "slot", strictly, it's usually the old "place on small tray that you push in"-type, which only extracts the payment when all the requisite coins appear to be there while being presented to the internals.
[2] Some are user-powered, i.e. hand cranked by the payee, others are wired up.