3D Printer Built From Legos, K'nex, and Glue Gun

This is pretty incredible. A guy going by the handle of JJmindstorm on a Lego.com community managed to make his own 3D printer with Lego NXT / Robotics Discovery, K'nex, and a simple hot glue gun. As you can see from the images, the main robotic components were created with the Lego blogs, and robotic elements, while the casing for the 3D printer was created mainly with the K'nex. Although a Hot Glue gun isn't the ultimate extruder, in tests I have seen elsewhere, it can work as a sloppy way to 3dprint an object.

None the less, this is an extremely creative way to build your own, very low quality 3D printer for probably well under $60. I'm hoping a video of this thing is posted soon. Would love to see how it works. If I find one I will be sure to update this thread:

http://i.imgur.com/cpt5zrv.jpg

I'd be curious to know where to get a Lego NXT alone for less the $60.

Perhaps if you break it down part by part that would be the cost.
I can not imagine this actually printing anything useful. Hot glue can get pretty runny and needs much more drying time than PLA would. Still an interesting concept for you. Credit to the builder!