Use the NADA price guides. For example:
http://www.nadaguides.com/Classic-Cars/1963/Jaguar/XKE/2-Door-Coupe/Values
and
http://www.nadaguides.com/Classic-Cars/1963/Jaguar/XKE/2-Door-Roadster/V...
Use the NADA price guides. For example:
http://www.nadaguides.com/Classic-Cars/1963/Jaguar/XKE/2-Door-Coupe/Values
and
http://www.nadaguides.com/Classic-Cars/1963/Jaguar/XKE/2-Door-Roadster/V...