I definitely do not recommend buying Bettas from stores that neglect them, for that reason. =/ Not only should people not be supporting that kind of abuse, but it's also going to result in heartbreak most of the time. Next time, buy from your local Betta club, a local or online breeder, or a reputable Fish/aquarium store... preferably one that has Bettas in spotless, large containers, and do not have Bettas who are lethargic/diseased out on display.

All of my Bettas have either been from breeders or a really nice LFS (just 2 from there) and live long, healthy lives. One of my CT's is from Petsmart and had severe finrot & swim bladder disorder, I only got him because a friend who works there just brought him to my house! It was a huge struggle to keep him alive, as the rot had reached his body. It was also costly to treat him, and required several water changes each week. I don't feel most people know how to treat many of the sick Bettas who come from poor conditions, it isn't easy! It'll save you money & heartache in the end to just pay the extra shipping charges to get a Betta from a consciencious breeder who loves their fish and takes great care of them from birth.