Don't know about obsessive in that one particular aspect, but I'm obsessive among other things about speed-safe Onions, collecting one of each of the whole range, and then pretty much all of the versions of the most affordable though by no means inferior ones, the Chive; have also bought 3 of one particular kind of Chive, but more so as to give away the extra ones to sheeples and ladies among my family and friends...
not much to brag about, I guess, and yes, I also collect Sebenzas, but more like each of a kind, not duplicates. Funds are limited, after all, and frankly, there IS a madness to collecting, isn't there, and getting exact duplicates, well that could qualify as insanity

Truly madly deeply into it,
t.