Really?? I find the opposite to be true. Everytime I go into a Petstop, it's only to kill time lol, I always leave empty-handed. If you compare the prices of say, fish food between Petstop and HFF, the difference is about $10-20. Their puppies are cute, but I won't buy fish from them. Their tanks are always covered in algae, have dead fish in them and generally don't show that they care for their fish as much as their furry animals. The two branches on Dominion Road and in Newmarket also have a couple of marine tanks which never have any fish inside but are constantly overrun with brown algae.
I hope that the branch in Botany is better managed, but if you're passing by the Dominion Road/ Newmarket branches, don't bother stopping by - you're better off driving a little bit more to get to HFF Mt Roskill.