I rode a Raleigh Grand Prix in the early 70s. Wish I still had it, cause it went everywhere, even though it was clunky. Now I am gifted with a Raleigh Competition, only with a small frame...I want to get an idea what it might be valued at so I don't get fleeced in the open market. It is in really great shape in the Portland Or area, and equipped with original parts. Do you have any ideas on how to value it?