Now that I have Menagerie 3, I stopped collecting for rares and started to collect for Breeds instead. If I am looking for a specific battle pet in the wild I would rather have a junk battle pet of the right breed than a rare battle pet of the wrong breed.
I'm actually getting At least 1.5 Battle Stones on average per day with my main (and only) level 100 account. And it takes about 20 minutes time to do it.
9 Charms from the Menagerie (8 from completing the quest and there is usually a 9th Charm in the Bag you get for completing the daily)
At least 16 Battle Stones from the extremely easy to get to Draenor Tamors (Frostfire, Talador, Shadowmoon Valley and Spires).
That's 25 right there and takes me about 20 minutes to do everyday.
If I have extra time in the morning I'll get Gorgond but I tend to get lost finding that one. It looks like it's right next to the Beastwatch FP but I tend to get lost. If I did that one it would put me at 29, just one shy of 2 battle stones.
I did Nagrand Tamer once but for the life of god I can't remember how I got there because it's past a proving ground that's filled with a bunch of top notch 100 killers that tend to wipe out my priest. I need to figure out the easier way to get there so I tend to skip that. If I knew how to easily get there I would be getting 2 battle stones a day.
I have found started new characters help level my new level pets. Now that I just got my 75th level 25 pet I now need to get my low level stuff leveled. I have a ton of highly rated stuff that needs leveled.