It is not a copy of a genuine coin; the only character normally to appear on a coin is bao, the one on the left. It's one of a class of Asian coin-like charms intended to invoke wealth and prosperity.
The four characters are, in Chinese, zhao cai jin bao which literally mean something like "summon wealth progress money" but more creatively, something like "May you have wealth and your money increase."
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis