OK . . . so how do I put a value on parts?

So I'm parting out a 68 barracuda convertible and I'm having a problem putting a value on some parts. How do you put a price on something when you rarely find it for sale? Example: Small bolt pattern kelsey hayes disc brakes w/ spindles?

It seems like alot of A-body stuff, but mostly barracuda parts are almost non-existant. Just wondering if you folks have some suggestions?

Thanks
Author: admin