If it's a 686-4, or even a 686-5 7-shot, thats not really a bad price. Not great, but not bad. The 686-4 is widely considered the "best" variant of the 686 by S&W aficionados.
The 686-4 was the last 686 to feature all forged parts and no MIM, and the 7-shot 686-4 was only made for one year.
The 686-5 introduced MIM parts and the frame mounted firing pin. After that the lock was installed, and I don't bother with keeping track of features after that.
Considering what the asking price for the new ones are, and what you get for that amount, I'd buy that pre lock 686+. It would not last long at that price on the S&W forum. Good luck with your decision! Regards 18DAI.