How affordable can a 3D printer be?

Stepper motors constitute a large percentage of the cost of 3D printers. This means if a cheaper yet reliable stepper motor could be used in building a 3D printer, that would go a long way to make desktop 3D printers more affordable. 

In this project, I investigated the 28BYJ stepper motors and their feasibility in a 3D printer.  

Unfortunately, the holding torque of these motors is just not enough for accurate printing. Lack of speed was also a huge drawback.