For $1 per person there is no better way for sports fans to spend a day with the family. The admission fee at most card shows is $1.
There are usually 20-50 tables at a card show and if you have 2 kids they can get 10 cards for $1 each or maybe 5 cards for $10 or even 1 card each for $10. That is cheaper than going to a movie and having it cost close to $50-60 with food. You can spend the entire day talking to the dealers and learning about cards as the dealers usually enjoy talking about the cards and sports. You also get to see thousands of different cards of your favorite players.
If you want to find a card show in your area go to http://www.beckett.com/showcal/showcalsearch.aspx
I can recommend 2 shows which are really good. 1 is located in New York on 43rd Street between 8th and 9th Avenues and the Holy Cross School and the other is in Garfield New Jersey at 490 Midland Avenue.