They live about ten years, it doesnt really matter to much where you get one from as long as it seems healthy, the older it is the better really as they are more likely to die in the first few months and they can be quick, particually for young children. Bearded dragons are one of the tamest lizards you can get and i have never known one to bite. i know my two and others i have worked with accept a lot of crap.

I too have used mine at youth groups and they deal with children on a regular basis so they get passed about and handled sometimes a bit roughly, having children crying or screaming, sticky hands etc, and they take it all in their stride.