I'm no S&W expert, but that looks to be a Smith & Wesson .44 Hand Ejector, second model. 6" barrels are the most common with 4" and 5" being very hard to find. I can't tell yours length from the photo.
Prices are all over the place. The value for the common models would start around $1,200.00 and go up, but any unusual feature could easily double that.
With best regards,
Don't get me out of my element here sharps4590, I'm an H&R man and no expert on S&W's. As I understand it this is a Triple Lock. It would be easy to tell if it Woods915 would be kind enough to post a picture of the left side of his beautiful .44 Special with the cylinder opened.
The Triple Lock was the first Model. The quickest way to tell at a glance that it is not a Triple Lock, is that the first model had a shrouded ejector rod.
That one has a naked ejector rod, so it cannot be a first model.
To see if it IS one, you can look at the right side, at the front of the frame, where the bottom of the barrel shroud is touching the frame.
In this picture it's an easy thing to see because it's not blue, while the rest of the gun is. You may have to blow the picture up, depending on your screen size. But that little "not blue" part is the third lock.