Unless you want to come with a new or improved system. You would be better off buying one. For a total cost of $38 you can have the whole package at your door in a few days. That's the Arduino, controller, and five stepper drivers. I do not see you doing it cheaper. With your schedule it is unlikely you could source all the parts and assemble them. And unless you have a well stocked junk box. You probably are not going to cheaper than a kit. Also some of the parts might be laser cut. But they are possibly do able on a CNC.

Have you looked into buying a used printer. I just checked Craigslist for my area. There is a used DaVinci XYZ 1.0 3D for $350.