Beleve it or not, Samurai swords can cost hundreds of thousands of dollars. This isn't for special historical ones, but for brand new ones. The reason is that a couple dozen people can be involved in the production, and it can take 6 months to make a single sword!
Authentic Samurai swords are made by forging process followed by heat treatment that is hardening and tempering. Material is carbon steel. Authentic samurai swords are quite expensive. Battle-ready Samurai swords could cost about $200-300 but may reach $1000 for better quality swords. Custom-made functional Samurai swords are priced at $15000-$50000.
It actually depends on the sword maker or the products used for the sword. If you want a very good katana which can chop down like everything, you need at least 3000$ for it. Do not ever buy one from e bay, contact a dojo master personally. Dojo masters should know well because every dojo has at least have one.
Authentic samurai swords usually cost thousands of dollars. Prices will often vary according to the sword maker and their experience in sword making. The quality of materials used to make the sword will also determine the cost as well as the type of artwork and detailing put into the sword.
The authentic samurai swords can cost as much as $30,000. These are the ones not mass produced. There are cheaper ones but they are not one of a kind. If you are a professional you can tell the difference between the authentic one and the mass produced. Beware of counterfeit.
An authentic samurai sword will very in cost depending on where it came from, what region. The minimum of an authentic sword is around $350. That's for either a damaged, newer or out of region sword. If your looking for a high quality well preserved sword expect to pay around $1,000 and over.