You will find that nickel-plated S&W revolvers are much less common than the same model in blue finish. Estimates are that some 10%-20% of any given model were made by the factory in nickel finish.

The are definitely scarcer than the blued models, and almost certainly worth more to the collector.

As for durability, the nickel finish is harder than blue, and more abrasion-resistant than the blued finish. It will resist holster wear much better.

Yes, a badly abused nickel revolver will develop nicks, scraps, and scratches on the finish, and may start to rust and peel. You will see this commonly on 10-year-old "working" guns, but seldom on the more modern ones, say made in the last 40 years or so. The modern plated finishes seem to be much more durable than the older ones.