[rhettyeakley]

Being materialistic is a human behavior, so I wouldn't call having old baseball cards being materialistic.

That being said, as human beings we should exercise moderation in all things. The moment baseball cards (or material things) become the center of our lives, we are then guilty of being materialistic.

So, I guess I would have to say no, but it also depends on how one is approaching their collecting.
-Rhett

Edited to add:
The way I like to think about it is along these lines...

If someone VERY close to you was dying, and the only thing that could save them is you giving up your collection, if at that moment you need to think it over for even a moment, you are probably guilty of a bit of materialism.