Soo... I paid $30 for 240m of ABS plastic. Considering both the totoros took ~ 5-7m of that, it works out not too expensive.
There's a 3D printer, the RepRap, with which the idea was that it could replicate itself. however there's only so much that it can do - for example it can't replicate it's pcb, the steppers or lead screw z axis etc etc.
#worth