[dheera]

Ask around if any of your friends have a 3D printer. For a one-off personal project that needs an RPi case most people with hobby printers would probably not mind. It costs pennies in materials, the only thing it uses is printer time, and hobby printers are usually idle 90% of the time.

For electronics housings, the material should be PETG, ABS, ASA, or any variant of nylon.

PLA is a bad choice an RPi case, it will warp under the heat.