Robotic Servos and 3d printing pens

Hi,

Just starting out and wondering if it would be possible to use a 3d printing pen instead of a hot end and filament feeder like

[www.ebay.com.au]


Also thinking that it would be easier to use robotic servo's instead of stepper motors like

[www.trossenrobotics.com]

Interested in your thoughts. These components look affordable and functional.

Actually this is a much more affordable robotic servo:

[www.hobbyking.com]