My dad makes his own powder horns as a hobby. We've accumulated about 30 of them now, more than we ever need to actually use. I've told him he should try to sell 1 or 2 just to see what they'd go for, and he's up for that.
However, we don't know what would be a fair price. These are heavily inlayed and scrimshawed, about 9" long. What does a handmade horn run these days?
Updated: I attached 4 pics of the only one I have on me right now. This is a fairly plain one with a nice stipled scrimshaw pattern and maple inlay. And a big piece of bone with the Star Trek Federation Delta. What can I say, I was 14 at the time he made it.