Could we at least name the pet shops you are not talking about on Springvale road? I'm guessing as Amazing Amazon is in Glen Waverly it is not the shop in question. As much as I would like to see bad shops go out of business, I would hate to see good shops suffer. I think it is owed to the decent shops to state who you are not reffering too.
In my experience Amazing Amazon has been pretty good. Their prices are a bit better than most and I have purchased two very healthy and well priced snakes from them ($220 for an MD and $230 for a Darwin). When I have been there I have seen no obvious signs of disease or neglect in their reptiles. The aquariums seemed in good shape too. Didn't take any notice of the birds, but large birds in small cages always suck in my opinion.