Yeah, most
sw fish our better off not being at a PETCO. I have to say though ours does a pretty good job, only because they have a couple of consciencious employees that actually know something. I have seen them go through their bad times as well.
As far as luck, sometimes I think that is half of it with
SW fish.

Luck and some knowledge will get you a ways in this hobby until experience catches up. When I bought my maroons they had not been there long and were sharing a small tank. I had just done some reading up and they were displaying all the signs of being a pair, so after several days of having them on hold I took my chances.
Good luck,