My guess is it could fetch far more than the $25,000 price but the article is fairly accurate. The Sturmgewehr was the original assault weapon (the article uses the term assault rifle but the press will never figure that one out).
Read a similar story the other day where someone had turned in a WW II Japanese rifle that has the morning glory on it, very valuable and rare for the model. The police are trying to find a museum to place it in instead of melting it down.