Second hand stores and flea markets may have them. I prefer the old knives.
I think it is because I like to ponder about how and who used them.
One I inherited from my father of blessed memory. I never saw him use it but I sure have and it keeps a good edge with a little touch up with a stone.
The other I bought at a second hand store ($10). I cleaned it up with steel wool and removed nicks with a file. Then, I sharpened with a stone as i described way back. I also bought a Swedish push knife in pristine condition ($6) at a second hand store.
You never know what you will find.
When I make my trade points I get them sharp, heat until red hot and quench them in motor oil.
I then re-temper them in my toaster oven when my wife is not looking. I put them in at around 350 for 20 minutes and leave them there until they cool.
I sharpen them more and continually during the season.
You could skip the heating and quenching and retemper. You would likely need more than 20 minutes because of the larger size involved. Of course, you would have to remove the handles.
I am not a blacksmith but that is what I do to my trades. Research more on line for your edification.
There's thousands of years experience on this site but you have to be patient with us.
Jawge