possibly because they are still obtainable, the just rarely come up for sale and are pricey af when they do.It's interesting that some people interpreted the question as "which rare blend have you always wanted but never had" while others chose to get more of something they've had but can no longer obtain.
Don't know, because I never had it!
I have a great assortment of blends, including some hard-to-get and out of production blends, but there's one that I would love to get a tin of, Georg Huber Virginia Golden Flake. Short of visiting Munich in the future, it's unlikely I'll see another tin of it. But that's the one.
What's your one blend?