The cost of a real Japanese samurai sword, also known as a katana, can vary greatly depending on several factors, including its age, condition, quality, historical significance, and the reputation of the swordsmith. Authentic and well-preserved antique swords, particularly those made by renowned swordsmiths, can be highly valuable and command substantial prices.

Antique Japanese swords can range from a few thousand dollars to hundreds of thousands or even millions of dollars, depending on their rarity, age, condition, historical importance, and the reputation of the swordsmith. Exceptional examples from famous swordsmiths or swords designated as National Treasures or Important Cultural Properties in Japan can reach the higher end of the price spectrum.

For modern, newly crafted Japanese katana made by contemporary swordsmiths, prices typically range from a few thousand dollars to tens of thousands of dollars. The cost can vary depending on the skill and reputation of the swordsmith, the materials used, the craftsmanship involved, and any additional artistic or decorative elements incorporated into the sword.

It's important to note that the purchase of authentic Japanese swords requires careful consideration, adherence to legal regulations, and consultation with reputable dealers, experts, or specialized sword shops. Due to their historical and cultural significance, it's advisable to approach the acquisition of a genuine Japanese samurai sword as a serious investment and seek guidance from knowledgeable individuals in the field.