Rick, post a pic of the bike and it will help.
Used bikes in good, clean condition will only depreciate so far and then the price levels out and gradually rises over time. An example is a 1973 Triumph Bonneville 750. I have been looking for one for several years. Good, clean original condition bikes can be had for around $3,000 +- $500. These prices have been stable for a while now. For someone who wants an early 80's California in good, clean condition, this is the price range in which I would list it.