wouldn't the nickel finish and 8 3/8" barrel be more desireable
I think the big strike against nickel is that while they are rather stunning when dead-mint, they wear...a lot, and they show that wear. At first you think "stainless?" but they don't wear like stainless.
If you are talking full collector package, a gun that's bought to be owned, not purchased so much to be shot, nickel is often a premium, but only when it's in FINE shape.
"Collectibility" is a funny game. It's often about production numbers, "rarity" and the like, more so than it is about tangible use. Collectibility has a pretty big affect on gun prices.