This reminds me of the coffee bar guy in Rome who was collecting money from around the world. My husband gave him a dollar - surely long a part of his collection - for our amusement purposes. This was a place by San Giovanni Laterano, which I mention since as we left that great church afterwards. we were approached by a german fellow (Dusseldorf) who claimed his wife's purse had been stolen, thus another bemused donation.
Not to be too cynical here, as I accumulated coins as a kid myself and still keep some from my travels for my own amusement - none of them are worth anything, since they are well used as they've all been in circulation. I won't be mailing them to anyone online.