The DC-3 is the kind of thing you hang in the atrium or lobby of an international airport or the executive lobby of your corporation. Calspan has a large (full scale?) version of the Bell X-1 hanging in their lobby. Northrop Grumman facilities I have been in have had similar items at various different scales. Dulles has some big stuff; if I remember correctly, one of the Gossamer birds with a huge wingspan. Ryan Aircraft had full scale Aerobees hanging inside the entrance.
Another kind of example is the Proud Bird restaurant on the approach end of LAX. It had full scale replicas of WW II fighters just outside their picture windows. The restaurant closed a while back but they decided to reimagine the style into some type of food court. They kept the big display models. It is probably what sets it apart and draws customers. Any place else is just another restaurant. The Proud Bird is undeniably an airport restaurant with a P-40 hanging overhead and a "hanger motif."
The decorating budget for a major corporation would not struggle with the price this guy is asking--if the model was a part of their heritage, was accurate, and they were rotating/replacing other décor. I think his issue is going to be that there is no Douglas Aircraft anymore, and no subsidiaries on the west coast that are of direct lineage. So he's probably going to need to work the airport remodeling guys. Or, if he's lucky, find a museum with a budget, assuming his item is really accurate. The Santa Monica airport would be a natural location, except that they already have a full scale version on a pole.
You are looking at an objet d'art, not just a model airplane. They are very different things, or the same thing in very different markets. Which is why I imagine that most of them are commissioned pieces, not just something that a modeler builds and thinks he can sell. (See prior discussion here in the Stunt Hanger.) Go look at the exact same issues with scale sailboat models. I recently saw a huge America's Cup racer (1/4 scale?) that a museum had commissioned. Gorgeous, but who would make one on speculation?
Dave