Dime store phonies 999,999 out of a million at those "Estate Sales".
What you have here is a needle in the pacific ocean. It's good and probably worth about 250-3 beans.
before reading Fudd's comment, I looked at the photo and it is not the common forgery that we typically see on this photo. Upon closer look, I also came to the conclusion that as long as this is not a reprint or copy, it is indeed authentic.