You could try Craigslist.
Also, you might want to post on the SewItsForSale group on Yahoo! Unfortunately, Yahoo has changed the format of all the groups so you may find it a little challenging to figure out how to join and how to post. I know the moderator mentioned that the rules for posting will have to change because Yahoo has disabled some of the old features and changed others. Still, it might be worth joining if you have the patience to work through the new Yahoo format. The nice thing about it is that there is no fee associated with advertising and selling your item. The worst thing (to me, anyway) is that you must be ***very*** careful when packaging a machine for shipment. If you do that, be sure to research thoroughly on the internet before packaging, as machines are easily damaged in transit if you don't know what you are doing. Of course, you could luck out and find someone in your area who is also on SewItsForSale who wants to buy your machine and could pick it up.