Value of a gun is truly in the eye of the beholder. I'm not sure if that is a 5 or 6", but a 5" nickel just sold for over 3,000 recently, but personally, I wouldn't give more than 1,000 without the box or papers. So to give you my opinion on value assuming it's a 5" and gun only, I'd say 900 to 1,000.
We need more photos. We need to see the sights and the other side. A big issue for me is whether it has been refinished? It's very nice looking though from what you've posted.