Perhaps it has something to do with the fact that they have swindled over a million USD for a glue gun which you can assemble at home in 20 minutes. Sure, people can spend their money on whatever they want but it doesn't make it any less ridiculous.
It is exactly this kind of overreaction that I was addressing in my original comment. You make these wild assumptions that it's only going to cost them pennies per unit to manufacture and that they're ripping people off. But that's far from reality.
Seriously?
Which is exactly what has happened here on two counts -
1) it is not a world first - http://www.thingiverse.com/thing:4156
2) it is not a 3D printing pen, it's just an extruder - exactly the same mechanism as that used in a glue gun.
2. Extrusion is the mechanism through which most 3D printing works. In this case, the extruder is attached to your arm rather than to a machine.