Ditto.
Congrats on the save.
The last time I was in PetCo (the LAST time I ever set foot in the place, permanently) there was a beautiful red betta in one of the little hellhole cups that was scraping against the sides - upon closer inspection, he was so sick that his skin was literally peeling off.
I told someone who worked there and they said they'd go take a look. I hung around in the store looking at stuff (or pretending to) for another hour just to see if they'd go look after him. At the point where I put all the things down in my arms and went out the door giving everyone dirty glances on the way out, no one had even gone over to look at him.
That store was 2 hours away from my home (I was on a trip, on my way back home) or I'd have scooped that poor little dear up and taken him home and nursed him back to health.
Petstores are E V I L.
So is WalMart. All 3 of my boys have come from either WalMart or some retarded petstore where I had to point out that their bettas were sick.
This world makes me sick sometimes.
By the way, it does sound like your little guy has some kind of fungal infection. You might want to treat him - I think it'd be worth it to make the trek for the meds. He'd appreciate it.