What Drives the Price Up | high-end katanas When a katana costs a lot, it’s almost always because of a combination of these factors: Factor Description Steel & forging material Traditional tamahagane, high carbon steels, differential hardening (hamon), folding / layering (as in kobuse / sanmai) raise price. Authentic craftsmanship Made by a recognized swordsmith (especially a nihonto, antique or modern traditional Japanese-made sword). Hand forging, polishing, detailing, auth