As I've stated before, I have no proof, but I'm betting across the US at least, late
roman bronzes/copper show up in cash register drawers more often than we may suspect. The
average cashier (not a denigration, I was one part-time in school) would look, puzzle a few minutes over the coin, and though any of us might, would not take the trouble to ever have it attributed.
As more of these coins become available, I'm betting it will be more common.
I myself must confess, I've put a few small groups of worn 3rd century coins in the sand at a couple of
North Carolina beaches just to add a
bit of excitement to the day of those early-bird metal detectorists
that hit the beach before dawn.