What everyone is trying to tell you is this:
Older (especially blued) S&W revolvers have been appreciating at a fairly steady rate over the last ten years, and will probably continue to do so in the foreseeable future.
I sold a 17-3 about five years ago for $400, and probably gave it away at that price.
I bought an 18-3 about the same time for the same price (that was the reason for selling the 17).
I am sure I cannot replace the 17 for that price, but on the other hand, if I were to sell the 18, I would get a bit more than I paid. Wish I could have kept both, but that's the way it is. I really prefer the 4" barrel, as it matches the remainder of my revolvers.