You ask about one "in good condition". This is very subjective - most are pretty beat up, especially the stocks. But, whatever you do, if you find one, don't 'clean it up' or refinish it in anyway. Collectors want the skull dents in the butt plate and the blood stains on the stock. These are a special piece of history.
You may or may not know that, during WWI the Germans protested to the International Court at the Hague against the use of the 1897 trench gun because it was "cruel and inhuman". This, during a war where poison gas was routinely used and not protested by the Germans. The reason they hated it so much was because of it's "trench sweeping" ability. An allied soldier would crawl across no man's land on his belly. Once close to the German trenches, he would leap to his feet, and cycle the action as fast as he could pump it (slam firing). Doing so would launch approximately 63 - .30 caliber balls at the men caught off guard in the trench (using buck shot shells).
On their own side of the front lines, the shotgunners would load the 1897s with bird shot. When the Germans threw hand grenades, the gunners would knock them down like ducks coming in for a landing.