You can get into pennant collecting very inexpensively. If you are into the Cardinals, there are lots of nice variations that typically sell for under $50.
Here's an example of a neat looking one that recently sold for a mere $10...
http://www.ebay.com/itm/ORIGINAL-196...p2047675.l2557
And this one for just $12...
http://www.ebay.com/itm/1960s-Vintag...p2047675.l2557
The $10 one was mid '60s, and the $12 one was early '60s. It's an easy niche of the hobby to enter, and you'll find that your taste is likely to evolve pretty quickly.
As for your Cardinals Pennant (posted above), it's either very late '60s or early '70s. It looks like the tip portion is probably altered.... be on the lookout for alterations like this, as you collect them. There are enough available in this genre, that you shouldn't have any trouble finding EX - NRMT examples, like this one below...
http://www.ebay.com/itm/vintage-late...p2047675.l2557
Hope this is helpful!