It's an incredible skill set. Some of the swords almost look transparent at certain angles, relative to the Hamon. Kamakura is considered to be the best era for sword making. Some of them are incredibly beautiful from this Kamakura era, when Masamune was alive and working. I'm thinking Kamakura swords could command several millions of dollars. They are imbued with white and black magic.
Kamakura Era (1184-1333)
After defeating the Taira clan at Dan-No-Ura, Minamoto no Yorimoto moved his shogunate to Kamakura. Emperor Gotoba, the formal ruler, remained in Kyoto. This also marked the beginning of the rule of the Samurai class. Kamakura became the cultural capitol, and swordsmiths from all over the country gathered there. These are the days of Masamune and his Jittetsu (ten disciples). Today it is generally agreed that the best blades were made in this period and, for quality and beauty, still remain at the top.
Osafune Mitsutada (Kamakura, 13th C) - Katana. Signature inlaid with gold.