Craigslist.org and eBay.com both have listings for used chainsaws. Type chainsaw into the search bar on either website for listings. Individual sellers on eBay have ratings and usually ship products sold. Craigslist recommends only dealing in person with its sellers to avoid scams.
Ebay recommends buyers closely examine the chainsaw description before buying to make sure it is in good condition and does not need repairs. When buying a chainsaw in person through Craigslist, thoroughly inspect it first. Look at the chainsaw's general appearance and wear. Make sure that the oiler is working. Check that the engine is working and starts easily. Some sellers may also offer a guarantee for rebuilt chainsaws.