Fed Tactical has the Lyman 1200 Pro Tumbler right now for $44.48.
Vibratory tumblers (mass finishers) of this type (relatively light duty) are used for dry media finishing and polishing. In this case they are being marketed to reloaders who use them to clean and polish brass cartridge cases before reloading, but they work well for all sorts of mass polishing such as jewelry. The media used is often sawdust or walnut impregnated with various polishing compounds. It is rated to hold 2 lbs. of media and will clean up to 350 cases at a time. I have a load of earrings going right now in my similar Midway tumbler, which is much easier than buffing.
1200 Pro Tumbler [fedtactical.com]