I honestly would consider buying from a reputable breeder instead of Petsmart. You could potentially buy from there, but I'd be wary. If this is your first, you may not be experienced enough to see a slight husbandry issue causing a big problem. I advise against buying there.
Most breeders would be willing to ship a snake to you, and you'd have more selection that way. Not only that, but prices are cheaper and a breeder will give you better care information. I like buying animals from HDI reptiles, but do keep in mind that they are on live. If not there, I've heard good things about BHB reptiles and I've talked to the owner, very nice guy. Just do a little research before you decide.