Do Currier and Ives prints go down in value?

I bought a set of currier and ives prints about 3 weeks ago (in the currier envelope and no frames)for $20.00 for 6 prints plus the envelope. RubvyLane and EBay have my same prints at $10.00 each and no frames. I had a brief talk with another antique store owner today and she told me currier and ives prints dont hold their value. True or not? Thanks,