The value of a real samurai sword, commonly referred to as a katana, can vary significantly based on several factors. These factors include the sword's age, authenticity, condition, craftsmanship, historical significance, provenance, and the demand among collectors and enthusiasts.

Authentic antique samurai swords, particularly those made by renowned swordsmiths, can be quite valuable. Prices for such swords can range from several thousand dollars to several hundred thousand dollars or more, depending on the aforementioned factors.

It's important to note that the market for samurai swords is specialized, and determining the value of a specific sword often requires the expertise of professionals, such as sword appraisers or experts in Japanese sword collecting. They consider various aspects, including the sword's signature (mei), tang (nakago) markings, blade condition, and historical documentation when evaluating its worth.

Moreover, it's crucial to approach the purchase or sale of a samurai sword with caution and to ensure proper documentation and authenticity verification. Due to the historical and cultural significance of these swords, there is a risk of encountering replicas or counterfeit pieces.

If you have a samurai sword you wish to assess or sell, it is advisable to consult with reputable experts or specialized dealers in Japanese swords who can provide accurate appraisals and guidance based on their knowledge and experience in the field.