I'm a little confused. Did you buy the coin and have it in hand? Or just thinking about buying it? If you have it in hand, I'd take it to a trusted individual (coin store owner you trust) and/or have a jeweler check the metal content. If you are just thinking of buying it, ask the seller to submit it to one of the three big grading companies to be slabbed, at your expense, and see what they say. If the seller is up and up, they may get it graded and prove it is real, otherwise, run the opposite directions with hands firmly on your cash.