Used brush cutters can be found on eBay.com or Craigslist.org. Farm auctions and equipment dealers often sell used brush cutters. Bulletin boards at your local agricultural extension office may have ads for used farm equipment.
Local classified ads sometimes list brush cutters for sale. The most common brands of brush cutters are generally the easiest to find locally. Hand-operated brush cutters are the easiest type to find. Larger brush cutters for tractors can require some time to source. An ad on Craigslist.org that states what type you are looking for can be a good way to find what you want.