It isn’t authentic. Someone got screwed if they paid that much for this fake. Compare the letters. For instance, look at the B in LIBERTY in both coins. If they aren’t identical it’s not real.
Not even a good fake. Compare to the real one: http://www.lincolncentresource.com/doubledies/1969Sddo1.html
Some of these are "bought" by a goon of the "seller" or the seller under a different name. It shows that "somebody else" bought it. Then it is relisted by the "buyer" at $100 more or such and others think " Hey, here is my chance to grab it" ! And thats how the money can be made. IMO, Jim