And no the Uncommon level stones you can buy with Justice don't count because we all know you don't go into Pet Battle PVP with anything less then Rare quality.
I propose that a Pet Battle Vendor be installed, this vendor would sell pretty much everything you have a chance of randomly getting in pet battle bags now.
Biscuits, leashes, etc wold be the cheap fun items. Rare quality stones and XP boosting items would be the pricy ones.
I'm not saying just hand stones out like candy, make them pricy, just make them a goal you can actually work towards without praying to RNG.
Pet Battle dailies can reward a set amount of currency, perhaps the amount goes up the more difficult the battle, and world pet PVE battles and random PVP battles can reward a random amount similar to how they can give you lesser charms now.
Stones could still have a random chance to come from bags, perhaps just lower the chance a bit.
I feel like this would bring some cohesion to Pet Battles and give them their own "progression" path to actually work towards rather then just hope and pray for RNG.
It's time we had a Poke' Mart guys.