I found their ad on kingsnake and I've seen them post more since I bought mine.
Out of 27 I have only bought 3 of my snakes in person. I've never had a problem with any of the others when they were shipped. Just check out their reputation and if they don't have many reviews or are new ask them a lot of questions about their packaging, who they use to ship etc. If you don't get a good feeling from the answers then just don't buy!