I dont think it would make much difference to the stores policies whether
FishKing5
purchased this fish or not but it probably makes a huge difference to the fish itself.
I think its a good thing to give the fish a chance at a decent life , even if a 55G isnt ideal its much much better then where it was.
The only way to stop all the big box stores selling fish is to not buy ANY aquarium related stuff from them, no fish, no food, no conditioner and no more $1 per gallon tanks on special. Money is the only thing the managers of these stores understand.
We dont have Petco here but have similar stores and they seem pretty much the same , huge places with a disgraceful aquarium section. I always thought if they actually did the fish section properly, got more variety of fish and used their national buying power they could easily take over the whole aquarium market. For some reason this hasnt occured to their management and we end up with half empty tanks filled with generic or dying overpriced fish. There are always people buying them though so they probably dont see the need to change anything.