when you can buy 5000 for $20 not really worth it.. I don't think you would be able to print a perfect orb.
3d printing works by laying down a strips of plastic one layer at a time building up the item. so round balls would not work all that well and even if you could print the balls accurately it would take a very long time to print enough to be worth while.. cheapest printer worth buying would be $150. You might still enjoy 3d printing so look into it for other items. search https://www.thingiverse.com to get an idea of all the possibilities!