I've seen my share of skinny, almost sickly looking petstore snakes as well, though I have to say I got my first ever ball from a Petco (overpaid of course) but she's been wonderful and I have yet to have any health problems with her in having her for a good year now (and when I got her she was actually really plump and healthy looking!). I lucked out though I think and would also advise anyone wanting to get into balls/snakes/any other reptile to check out breeders first: better chance of them eating, being healthy, and at a better price to boot.