To place a price on this sort of thing can be a difficult thing. However,
you might want to start looking at the EBAY on-line auction site at:

http://www.ebay.com

and use their search engine to look over the site for similar items. I did
a quick check for you and found a set of 31 Arm & Hammer bird collector
cards that sold for $31. Obviously, the value of your cards depends a
great deal on if you can find an interested party and the condition of the
cards.

By the way, this website is a great place to keep an eye out for all sorts
of bird related collectibles. I have purchased several nice, old
collectible bird books here and never have had a problem. I've also sold
some things through this service and have yet to have problems with these
transactions (knock on wood).

Andy
ajstudio at ptialaska.net
Anchorage - Alaska