Both are great games. I prefer CFTBL over Spiderman, and given your age you may also because of the theme. CFTBL has a great theme and easy to understand rules. Given both are in similar condition, Spiderman will usually cost $500 - $1000 more, so if they are the same price the Spiderman sounds like a better deal. IMO Spiderman ball times / games tend to be too long, which you may or may not like in a small collection.
I realize I've just given pros and cons to both choices, but I hope the info helps your decision.