How much is a Wayne Gretzky Rookie Card worth that is autographed on the back of the case?

If the autograph is on the card itself, it can fetch up to $3000. If it is not on the card, it will fetch much less. The card itself (O-Pee-Chee) gets anywhere from $400-$1000 in excellent condition. Shortly after his first child was born, he signed his last copies of his Topps and OPC rookie cards, and supposedly hasn't signed any since.