tmor:
I hear what you're saying but I must disagree in part. I've written this before and probably will do so again....thinking that the 1876-CC 20¢ must be part of a 20¢ collection is the same thing as saying that the 1913
Liberty nickel must be part of a
Liberty nickel collection. No way! There were a few more of the 76CC pieces available than the Nickel but only a handful. I consider neither of them as a collectible. I don't think that any 20¢ folders or albums (I could be wrong...but I'd be quite surprised) have a hole for the 76CC. It's not an obtainable coin to the vast majority of collectors...hence not a collectible in the classic sense. 1901S Quarter, 1916 Quarter, 1922 Plain Lincoln, 1955 Double Die, are extremely collectible, albeit very expensive depending on your budget.
The 20¢ coins are traditionally gone after for type. I think people are generally not interested because it's only a 4-coin (for all practical purposes) series. The 76S is extremely available in ALL grades. I agree that the 1876 is very underappreciated, not in strong demand, and priced much cheaper than you might think supply might indicate (not a lot survive, especially in nice original condition in any grade, like this one).