I wanted a laugh, so I just looked at the census. Not exactly rare in higher grades.
Neither is Hulk #181. What's your point?
Wolverine is a slightly more popular character than Iron Fist, but who knows, maybe he will launch into stardom and kids will dress up like him for Halloween next year.
It is surely less known internationally. Wolverine became popular in Italy just in the 1990s, as most of the previous material was left unpublished (we did not have a publisher from 1984 to 1987), and Iron Fist was just partially published in the Shang Chi magazine here, so a lot less popular than Wolverine mostly for that reason.
For example, the first apperance of Sabretooth in Italy is published within the pages of this book (in black and white, as all the Shang Chi series was B/W):
Cool book! (thumbs u