I am a simpel hobby maker, who has no interest in making sheaths. it takes me long enough to finish a knife, so I don't want to fiddle with sheaths too! I have only sold one knife, but what my plan is is to offer the knife as is, or the knife plus a sheath made by a local sheath guy. The guy I go to makes AWESOME work, very inexpensively too. I think it is advantageous for me to do this. I can concentrate on what I want, and if I sell a knife to someone who wants a particular sheath, they can get that sheath made.
I.E. some on the forusm would prefer a sheath from Normark, some from River City, maybe soem want a nylon sheath from SOE. I can make the knife they want, and someone who is geared up for it can make the sheath they want too.