For what purpose?
I think that anyone should try every keyboard at least once, if possible, and that anyone should have enough of good keyboards for every computer you own and/or use (i.e at work).
However, I think that one should try to avoid getting caught in a collector mentality and try to get all varieties just because. In my collecting (I am not yet that much of a keyboard collector), I strive for quality over quantity. Only the best items, by some metric that is of course highly individual.
Poll