I suppose it depends on what it costs you to acquire the revolver and what you intend to use it for. A good commercial blue job can cost between $150 and $300 depending on the prep and polish. I think S&W prices for a refinish fall somewhere in the middle of that range.

If I were able to buy the gun for $200-225 and intended to carry it or use as a truck gun, I would probably spend for a low end blue job. If it was just a range gun, rust can be prevented with oil or wax.

I've never tried to do an entire gun with cold blue, but others have and are happy with the results. There are home bluing procedures that are time intensive but give an excellent finish.