If you missed out on the Ohtani 50-50 ball, you might have a shot at the Freddie Freeman grand slam ball from Game 1 of the World Series. It probably deserves its own thread, but given how much the Ohtani ball went for, and the historical significance of this one, I'm guessing it'll go for at least a million.
Freddie Freeman's historic World Series grand slam ball to hit auction block
(Screenshots show Freeman about to make contact with the ball, and the ball in flight)