British BLNE are a deal right now and generally have always been so.
12's in particular. Smallbores significantly more expensive. They didn't make nearly as many of those as 12's. Even more true than in the classic American sxs market, where far more 12's were also made.
Re selling, I've had very good luck working with Mark Beasland to sell guns on consignment for me. If you follow his inventory on GI, guns seem to move pretty quickly. Admittedly, I live close enough to Mark that I can drive my guns down to his shop rather than having to pack them up and mail them. But he also shows up at various sxs shoots and big shows (Tulsa) where you can deal with him face to face.
