Welcome to the site.
I think 67's are as popular a car as 70's when it comes to the price. Most 67 convertibles are up there in price. A nicely restored 67 goes for big money from what I have seen.
ACES (American Chevelle Enthusiasts Society) put out a magazine if you are a member called Chevelle World.
http://www.chevelles.com/aces/
Chuck Hanson is head of that group and Flash on here has drove across county with him to come to our show a couple of years ago.