We've done some songs for church and other special events that have called for the dulcimer. A few years ago, when it first came up, someone had one that they didn't play, I got to look at it, and said, "Well that can't be too hard." So now everytime we need a dulcimer, they call me and I get to learn a new song.
As for selling equipment, what do you have? Some of us might be interested. Hmmm, maybe we need a musical instrument classified here.
Other than that, I've bought from Ebay, but never sold there. As far as buying, it's hit or miss. I bought an acoustic bass...miss, and an old trumpet...hit. It's convenient, though.