If you live in a major metropolitan area like NYC, LA, or san fran, it's worth trying to find a local buyer on
craigslist. It's free and easy to use... no registration required. Just make sure you "anonymize" your email address, otherwise you will get a lot of scam emails. The good thing about craigslist is since the buyer doesn't have to pay shipping and the seller doesn't have to pay ebay fees or deal with packaging, etc, you can sell it at a cheaper price and still make the same amount of money.
Your second option, of course, is ebay. You might have trouble getting a good price for it though if you don't already have an account and some positive feedback. it looks like the going price for your machine will be around $1500-$1600.