I'm pretty sure that around here, a minor can not buy a vibrator, just like they couldn't buy a playboy. Don't think they're allowed in the stores either.
Not that I would go into one of those places. That's what the internet is for.
and even if they're is a age limit on masturbation (which would be S T U P I D) there is no way to enforce it. I mean what are they gonna do, watch every minor, then get charged with Child Porn once you do?