Which "dash" number is it? The -3 came out in '82 I believe & the change in serial number from "N" to the three letter started around '87. What's the barrel length? If it's a -3 or 4 without the box or papers for me I'd stop at $650, $700 absolutely tops if I was really hot for it (I prefer the 4"). Prices do tend to fluctuate a bit depending on region.

fyi the "Dirty Harry" gun is a 29-2 with a 6.5" barrel if you're trying to duplicate that one. I lucked into one years ago & sheepishly admit it's the only firearm I wanted strictly because of a movie lol.