The proof-of-play era lasted only about 6 weeks in May/June and about 800,000 coins were mined in those days. After that only rarely it was possible to human mine some, perhaps it's still possible to grab a few but haven't tried lately. Easier to buy a lot for little investment but that's no fun I guess. I'm still keeping some. POS integration would give more incentive to buy them but the botowners would get even more advantage so I guess it's too late now.