A show quality Carter 539S W-O is $299.99. If you have the original NOS box, and it is a NOS carb, you could ask for more. No guarantee that you'll find a buyer, but it is a start. You may want to check with
http://oldjeepcarbs.com/ to get a better idea of the current worth. He deals with the carbs everyday, so I would think of him as being more helpful.
Thank you for your question!