They are not fake, they are just made cheaper for a mass market. I consider the mass-produced swords that this forum is mostly dealing with to be in the same category as the other things we get from China, like TVs and Radios, and everything you can buy at Walmart. I dont use the term 'Fake' to describe swords and fittings made in China. Im on the road right now, but it is on my list of things to look into. The sword itself is from Japan, but the little blades and the matching guard would have to be taken apart I would guess to see if they are signed? Websites that sell antique katana will sometimes list kozuka and kogai, and you can find prices that way. Modern Chinese fakes like the ones in your photo can also be had for the price of the sword they come with, so that puts an upper limit on what it would be worth for anybody to buy just the kozuka and 'kogai'. Don't know of any cheap swords with reasonable kogai, either. The cheaper way to get a modern one is to buy one of the Musashi katana that come with one (about $60 last I looked). Kogatana (kozuka blades) can be about $50. Good quality modern ones can be about $100-$200, or more. Just a single kozuka, handle only without a blade (the blade is a kogatana), can be in the medium to high $100s. Matching sets of antique kozuka (the knife technically, the handle only is the kozuka, but it's used to refer to handle + blade) and kogai (the spike/pin/other thing this is what your other knifey thing is meant to imitate) of reasonable quality will easily sell for $100s-$1000s.

Fake katana walmart