Overhead shots can be very valuable in certain types of product photography or even artistic compositions. But sometimes you're in a budget. However, this shouldn't stop your creative work. Instead, look for other ways of making those shots with a cheaper gadget.
Here's my solution.
Step 1: Materials
You will need:
x1 double pulley
x3 screw hook
x3 round hook screws
piece of wood (a heavy one for stability)
nylon rope (see how long do you need it to be).
Step 2: Set Up
# Screw the 3 curve open hooks to the ceiling in a positioning that best suits your needs
# Hang the pulleys and pass the rope
# Screw the round hooks to the piece of wood on the extremities and tie the other end of the rope
# Have another hook somewhere in a wall for you to tie the rope when you move the height of the rig.
# Attach a camera mounting on the piece of wood. I'm using one of my camera mountings directly screwed to the wood but you can also look for other options, perhaps some mounting screws.
Step 3: Enjoy!
Adjust the bar to the desired height depending on what you're photographing.
Be creative and have fun! :)