Scares is fine, if it is high quality. Otherwise it's just one of a few. Would you consider a 1972 Orange Pinto scarce because I know where there is one or would you rather find the 65 Mustang with less than 100 miles on it? Both are scarce but one is rare and the other is just unusual at best. Not many early Ithaca 20's but unless its high condition or high grade it is just interesting at best.
Agreed, that is why I used the term scarce, and not the MUCH overused term of "Rare". I have owned a couple of flues and NID 20's over the years, but never encountered one with 30" barrels, which I find as interesting. "In the eye of the beholder" as they say. Regardless, I paid very little for the gun, and am enamored with long tubes on small bore gun!