Without knowing it was a bad idea, we got our beardie from PetSmart. She was roughly 5 inches when we brought her home (I didn't measure her until she had been home a week and at that point she was 5.5 inches). We were just in our PetSmart the other day and they have teeny tiny babies, I would guess no bigger than 4 inches. Like you said, one was very alert and looking around but the other 3 or 4 were just *basking*. Thankfully no one was being dominated at that time, but if I had the space and money I would have been tempted to buy them all.
I will say, our beardie was the only one in the viv when we bought her (which makes me wonder if she was the last one to go) and she wasn't very active there, but at the time I really didn't realize that was something I should be looking for. Once I got her home and found this site, and found a few things that PetSmart hadn't shared with us, within a few days she was pretty active and eating much better. We ditched the freeze dried veggies and went with fresh, upped her feedings to 2 a day and she's quite a happy little fatty now. She eats her crickets either 2 or 3 times a day, depending on how she's acting and she's settled in quite nicely with eating her greens. In the time we've had her (about 3 months) she's grown almost 7 inches. In the future, if we ever have another beardie, I will insist on going to a reptile store, or we have a *reptile show* in our area once a month that I've heard very good things about, we'll go there. Never again will I buy a pet from PetSmart.