Is it blued, stainless steel, or nickle? There no such thing as blue nickel.
The Dan Wesson spent their production dollar on the outside to give it a near mirror polish blued finish or a satin stainless steel.
Unless it was some sort of very limited special production I don't think Dan Wesson made any revolvers in bright nickel.
Dan Wesson made several models, and the model, caliber, and actual condition set the value.
In .357 Magnum Wesson made the models.......
Model 11 fixed sights, blued (1970-71 only).
Model 12 adjustable sights,blued (1970-71).
Model 14 blued (1970's)
Model 15 blued (1970's)
714 Stainless steel.
715 Stainless.
All these were very similar with only minor details different from model to model.
One source of getting a ball park value is to look for similar guns on Gunbroker.com and do a search for "Finished Auctions"..... that's what the actual sales price was.
Another is to do a detail search on this site..............
The prices there are only general values that may be higher then the actual market value.
Much depends on the actual condition.... a well used gun is not as valuable as a near new model.