You definitely should think of it as rescuing, and that I have! Petco's around me have NO provisions for stressed fish or invertebrates. Even though they say they do. For eg: Raccoon butterfly, full on ich, brought it home into the QT $15 full recovery. Blue tang HELLE plus fin rot brought it home to the QT $15 out of QT well on its way to full recovery HELLE almost gone. leather coral, NO polyp extension for weeks there, and $7 now its a monster! I am not saying you are getting a deal, because if you add up the meds, salt, time, etc. you are paying way more the the initial value of the fish. Not all has been good, there was a malnourished Scopas tang that I was trying to get them to adopt out for weeks, but by the time they did it was too late.
Petco's have no business selling saltwater fish and inverts because they take no responsibility for them. They are just another cog in the wheel of what is wrong with this industry, making profits on volume instead of quality. They are not alone in this fault, and we have to do what we can to encourage change, before ppl. not in the industry do it for us.
Stepping down from my soap box...
P.S Does anybody in the LA area want to buy a fully conditioned "great personality" Raccoon Butterfly?