3D printing is hot! After 46 hours this kickstarter project is already funded. http://www.kickstarter.com/projects/printrbot/printrbot-your-first-3d-printer
One of the appealing aspects of the projects is that the printer is once again a few hunderd bucks cheaper. Other projects try to reduce the price by recycling parts (see for example http://forums.reprap.org/read.php?152,97849,106878,quote=1 ).
It is clear that the price will go down in the near future. One option is to use only one engine as the figure below illustrates. The top is not flat but skewed, the printer nozzle goes to a certain position because of this. There is a point 0: where the printer nozzle starts (because of the gravity effect). One engine can cover the x, y and z-axis and print objects since he only has to pull one side (the other side is covered by the gravity effect).