My suggestion would probably be E-Bay with a minimum bid amount added, i.e. you can list it with a starting bid amount. To give a little notice you could also go to some of the figure sites such as PlanetFigure and let folks know it is out there.
This would give you a bit wider of an audience.
I love Bill's work and have the Andrea book of his work. He has a wonderful ability to depict soldiers in their natural element and usually a quick glance is enough to identify one of his figures so recognizable is his style. (Part of his charm has also been his admission of painting figures using Humbrols etc. when everyone else was using oils and acrylics because he didn't know any better. Can't argue with the results though.)
Good luck.
mark
