That's the problem with the '67 coins, but often they're cheaper because of the uncertainty of the content. But at a good coin shop, they'll be tested and priced right, but at a flea market, sometimes they're just priced as 50% coins, and you can get a great deal like that.

Either way, I always loved the Centennial sound, and used to save them since I was a kid from my change. I have quite a few 67 pennies and nickles I've pulled from my change and kept for ever. Now I keep the painted quarters, and commemoratives.