Jonathan,
Some folks think that their clocks and / or watches are worth more than the market would bear.
I can suggest a few options?
Dig through auction sites for the style/size/brand of clock you want to start with.
Keep a log based on that criteria, and see what the actual sale prices are . This way you can build an idea as to what they are really selling for on the open market. Also keep track of whether or not they were “as-is”, or refurbished, as that is really important knowledge when you are trying to barter a price based on condition.
There are also books out there for valuation of clocks and watches…many are available in your local library, but it not, you can usually find used books on the subject. You will find that the values don’t usually change much for the 1st few years after publication. Hope this helps
Regards,
Randy