Hmm, I have a bag of beer caps, approx 10" high, 4" x 6" footprint. Collected from my beer drinking in the home pub for the last 2.5 yrs. I will note it doesn't include the caps already in one of those decorative boxes with clear front, and of course we drink draft beer at home far more than bottles or cans (three taps available, usually an IPA, a stout or porter, and then "something else" like a Belgian Tripel or Farmhouse or brown ale or barleywine, or...)
Anyway, maybe I'll do a quick count just to amuse myself, since that one bag is a lot smaller than what I have seen depicted so far!
In the meantime, my guess is 4380 total, 86 green.