3D Printed Quadcopter
Print the Pieces
The creator said that he used PLA, .25mm layers, and 40% infill, but you can do what you want. The total printing time is about 5.25 hours at 4500 mm/min without the optional posts and post plate. (If you do not know what these are then read the Thingiverse page again)
Assemble the Pieces
Now it's time for assembly. This might take awhile but if you want this then it will not be so bad. First watch the videos on the Thingiverse page and then assemble the quad. I'm not sure what to total cost of the electronic parts are but it won't be too bad, probably under $50 US.