The total value might not be that much, but I believe that the fact that they are "together", the collection as a whole should be worth around that money (efforts for collecting, etc).
The accumulated effort of building your house – and thus the worth – is encapsulated right there in the number of rooms, location, and condition. In fact, I'd bet the human effort in building a house (planning, building, decorating) is more than the cost of bricks and mortar.