Actually, the pin does more of less date when it was made. They stopped pinning barrels and counterboring the cylinders sometime around 1982.
Whether they are better without the pinned barrels or not, the fact is that the pinned barrel models are more desirable than the unpinned variety. Those looking to collect S&W revolvers will generally pay a premium for the earlier guns over their later cousins. That's why the prices were higher for the earlier guns.
The same can be said for the S&W's with no MIM parts or the internal locks. There is a perception that the revolvers that were made before those features were introduced are better made and there are people out there that won't own the latest production models.
I personally see no real functional difference between the early vs the later guns.
I do however, collect pinned barrel Smiths and prefer the 5 screw models.