Any reputable breeder will have a live arrival guarantee. If you're buying online and this isn't part of TOS, don't even consider it. If you choose to go the show route, find out who the vendors are and do some research on their rep prior to the show. I suggest the classifieds right here on BP.net as a good place to find snakes from reputable breeders. They may not be large, but with little effort you can determine those that have excellent reps on this site. If you chose to go with 'large reputable dealers' such as those suggested in a previous post, be aware you will pay a premium.