I would say it completely depends on the quality of the store. If you believe it is an outstanding store with fantastic service and knowledgable staff, plus excellent living conditions for the animal, I'd say yayQ
...However, if it is like most pet stores people talk about with medeocre quality, unknowledged staff, and dirty/inappropriate living quarters for the animal, I'd say nay.

I'm not against all pet store animal purchases, but for snakes I am personally. Especially when I see other species not being properly cared for. Even dead fish floating in tanks is very discouraging for me.