Do you know the actual value of the cards in your collection? Or do you have an estimate of their value? What do you think is the most valuable card in your collection? For me, the most valuable would be the lone Michael Jordan card that I have. It's a 1997 Upper Deck card. I think it's value is just about $1 to $2 dollars but this card holds a special place in my collection and consider it as the most valuable.