We used to drop by the pet store when my son was that little, saw many interesting animals, which was good as a lesson, but not anymore. I don't how it is where you live, but here the poor animals at the pet store are sad and I wouldn't want my boy to get upset. (Not to mention that I couldn't save the animals there if he asked!)
There are pet stores here like that, too, and it makes me sad... Luckily we have a nice one! This pet store only gets one or two of each animal at a time, and they get to run around the store! :) I love going in there... The big chains, not so much...