A friend has asked me to try to determine a value/asking price for the following shotgun which he won at a DU dinner about 13years ago.

New and unfired in DU hard case
--American Arms Sterling 12 Guage (made in Spain)
--28 " vented rib
--3" chambers
--hand checkered walnut stock
--coin finish receiver with english scroll work with Ducks Unlimited Canada engraving
--one of 600 in series

Any ideas what he should expect to get for it?