There's another story of the pawnshop symbol.

It says that there was a man who had gone into such poverty that he was at his last resort: selling his daughters into prostitution.

Saint Nicholas of Myra heard that about this, and in the night threw three bags of gold through the window, and the girls were much relieved. Those three bags of gold grew up to be the symbol that denotes a pawn shop, and old Nicholas grew up to be Santa Claus, among other things, and patron saint of pawnbrokers.