Around here, if you are talking gun only with original wood grips in 95% condition I'd guess you would be looking at around $500, give or take $50 depending on who is selling it. It might even go close to $600 at some of the LGS.
bought a 4" 686 in once fired condition at a gun show ( before entering the show , and old guy had it in the lobby and we made the deal ) for $275 ....needless to say it is a keeper and i know i was in the right place at the right time !!
I recently bought a 686-4+ for $300.00. I was prepared to pay much more. Before ya'll hammer me, the guy I bought it from made money on it when he sold it to me.