There's a fine line between a "what's this worth" or "" question and a disguised ad (subscribers can place a FS ad, members can't). But I'll assume it's a genuine request.
By in large, there's little interest in enlargers unless they handle 4x5; with the Leitz Focomat being an exception. Frankly, I think it's unlikely that you'd get much for a B8 that needs to be shipped. But it's certainly worth a try. Depending on your location, CL might be a better bet.
Personally, I wouldn't buy an enlarger off of ebay unless it was someone with knowledge of it's working condition. But if I wasn't in a large metropolitan area, I might change my tune.
If you want to the most for it, then make sure you describe all the negative carriers, lenses, and lens boards that go with it. When you ship, pack the bulb separately. Make sure you have a suitable box for it and know how the dimensions effect shipping cost. I apologize if I'm telling you things you already know.