Your best bet is to buy a beckett price guide from any of the nearest sports card shop. This will help you to know the exact value of the cards that you have. One thing that actually matters when it comes to the value of the card is it's condition. If the card is in good condition then it will have a good value. There is one more thing which will definitely help you a lot. You can check the value of any sports card from the following website.
beta.beckett.com
beta.beckett.com
