Make them a tad more common from pokestops please. I've done well over 100 to 200 pokestops without getting 1 stone and whichever i get won't even bother me.. I can do this amount of pokestops because i can warp and fly(Champion rank) End of rant
They are perfectly obtainable and have been made rare for a reason, they can be easily obtained from pokestops as well as can be purchased from the mystery man for tokens.
It's just luck based, I've managed to collect 5 of them after only playing for 3 days. I think the rarity is fine, making things more common decreases there value which isn't great.