Owned doesn't always mean no overhead. It just means the bills come one by one. There is certainly a case of reputation. You can find small knifemakers all over the place who will work at near cost, and low value labor. Its hard to find them, and some suck. Same like tattoo artists, there are a lot out there, some will stay in the business for decades and become the "known names" some for good, some ill. And many will go get "real" jobs and leave it behind, like many other artists, musicians, etc.
Often there is a certain trust level with a tattoo that has to be bought by the artist, at least until they have a very solid reputation. With knives its warranty and customer service. The knives you see in a store are the tattoo equivalent of a franchised shop, or in the high end, the Kat Von D level of reputation, where even non-tattoo people recognize the name. (also some brands have 100 some years of history) Also keep in mind that the time spend for you is the end of the transaction, for the knife maker its the beginning, most are working on spec, so they have to hope a piece sells. Just a different business model. (and a lot more hours per piece in many cases)
A little note on community here. If you want offense you will find it. Many here are far more sarcastic than mean, so if something can be read as sarcastic or mean, it probably is sarcasm. You'll know when its mean, and it won't be out here in the general forum. We are all here to have fun, its been a tense week for many, so that might be part of why some are a little bitey today. You hang and be chill, and it all goes well (that isn't to say you have to agree, but don't take or make it personal) you let stuff get under your skin (pun intended?) and there are member here who will burn you to the ground. Its sort of a test of character (an often dumb one, but hey, its the internet!)