Posted By:
Max WederLeon
I don't need to reiterate what others have said about the warning signs of his query (which signs I agree with; I would add: he is certain the cards are authentic, but can't grade them?), but just to point out: Windsor (the seller's stated location) is at the border of Ontario and Michigan, just across the river from Detroit. In fact, Windsor is actually south of Detroit.
There is thus nothing unusual for a person in Ontario to attend a card show in the United States and even to bring cards to such a show. The border wall is not yet that impenetrable.
Max