Thomas Edison in a 1902 Ogden's Guinea Gold in pretty good shape for less than $4.
I'm not sure if he ever played ball, but his light bulb sure comes in handy for viewing all our cards.
The rest of the cards are all were obtained for less than $5 : Soccer, Golf, Horse Racing & Boxing
I also have 28 T51 Murads with sporting figures all for less than $3 each.
Parenthetically all of the above except the Edison and the Murads are graded with grades ranging from 5 to 8.
Not a B/S/T thread so I wont mention that I would sell any of them for $20.