Since it is in such good condition and you've seen similar items auction for larger amounts, the best thing you can do is take it to an independent appraiser and then get it insured. If the first appraiser does not give you what you believe to be a fair appraisal, take it to two others. That particular appraiser may not specialized in antique appliances. Do not take it to an appraiser that owns an antiques store as they may give you a low appraisal and then try to convince you to sell the item to them (hence they capitalize on the true worth of the items). Without having pictures of your item, there isn't a way to appraise it online. Even so, most auction houses require that the item be viewed in person for verification of the quality of the item.

The next step is to get the item insured. If you have renter's or home owner's insurance, just add the item specifically to your policy and make sure your coverage is high enough to cover the item. Then have your insurance company send you a certificate verifying insurance on the item. Once you've appraised and insured it, the higher-end auction houses will accept it with a high minimum bid. Next, begin shopping the auction houses. Some of them will charge higher percentages of the sales while others will charge a flat fee.

To shop around auction houses, make digital scans and copies of your appraisal certificate & insurance certificate. Take no less than 5 high-resolution pictures of the item on a plain background (preferably white). Be sure to photograph any markings, engravings, identifying features, etc. Contact the auction houses and they will guide you through the listing process. Every auction house has different procedures, but they will all need photographs and appraisals in order to determine whether or not to feature your item.

The auction houses you will want to contact are
Doyle New York: http://www.doylenewyork.com/
Northeast Auctions: http://www.northeastauctions.com/
Skinner Inc : http://www.skinnerinc.com/
(You may find the best bidder here as this is a Massachussetts based company.)
Bonhams & Butterfields: http://www.butterfields.com/

I do not recommend auctioning an item on your own as you will not get the full value of the item. eBay, Yahoo Auctions, etc are known for bargain-shoppers and not high-end antiques enthusiasts. =)

I hope this was helpful to you! Thank you for the clarification.