"What's it worth?"

[427TJ]

Lots of these threads on various car forums these days, both cars and parts. I suppose it's a form of advertising (getting around classified ad fees) and/or genuine lack of knowledge of value. Why not list something on eBay with a reserve that's up there and see who bites? If it's truly valuable or needed by someone then the market should tell you? Yeah, that can be called fishing but isn't that kind of what a "what's it worth" question seeks to do--'fish' for an answer?

Thoughts?