The value of a real katana, a traditional Japanese sword, can vary significantly depending on various factors. These factors include the sword's age, craftsmanship, condition, authenticity, historical significance, provenance, and the demand among collectors and enthusiasts.

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

Modern, newly made katana swords can also vary in price. Custom-made or high-quality production katana swords crafted by skilled swordsmiths or reputable manufacturers may cost several hundred to a few thousand dollars.

It's important to note that the market for katana swords can be complex and specialized. Determining the value of a specific katana 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.

If you are looking to purchase or sell a katana, 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. They can help determine the fair market value of the katana based on its specific characteristics and market demand.