Who wants to start a business? A legal "high" for $25. I know I would pay $25 to try this thing out and I bet hundreds of people in any given town would too. Only takes 40 people to recoup the cost of the machine.
In theory any sufficiently powerful EM field could kill a person. However it's fortunate that magnetic fields diminish significantly with distance, so the primitive parts of our brain that control bodily functions are relatively protected so I wouldn't be surprised if they start researching ways to use this as a stun weapon.