There are numerous online auction web sites, some that you list yourself - think eBay, others that are operated on consignment. If you're looking to add to your collection or perhaps start selling it, these are often a good option to consider, especially if the collection is valuable.
Also check search engines, such as Google by doing a search for your particular collectible with the term "online auction" to see what else pops up that might be more specialized and a better fit.


Tips:

• Is the auction house an appropriate place to buy or sell your collection? Do they sell similar items?
• Look at completed auctions to find out what prices were realized.
• Check listing, completed auction fees and other extra costs to make sure there are no surprises.
• When buying, be sure to factor in the Buyers Premium to avoid unpleasant surprises when you win the auction.

Online Auctions

• Bertoia Auctions
  If you're into vintage and antique toys, this auction house is a must on your list. This auction house deals in high quality items, produces beautiful catalogs and is worth a visit. If your collection is particularly noteworthy, this would be one of several auction houses I would chat with before making a decision on where to sell items.
  
  Collector Auctions
  The categories are Toy Trains, Scale Trains, Railroad, Collectible Toys and Transportation Toys, and NASCAR, IRL, CART and other racing collectibles.
  
  eBay
  The biggest and best auction online for collectibles. If you can't find it here, it probably isn't available or doesn't exist.
  
  eBay Stores
  Open a "store" on eBay, it will show up in auction listings and related searches.
  
  Gallery of History
  Also includes a direct purchase web site.
  
  Hakes
  One of my favorite spots to shop. This is one of the first places I would check about consigning my collection for auction. Check out their schedule and order a free catalog of the next auction. They specialize in everything from toys to political buttons.
  
  Heritage Auction Galleries
  Sports, movies, autographs, coins, comics and jewelry -- Heritage sells it all. One of the biggies and one of the best with lots of resource information on the web site.
  
  Manion's International Auction
  Manion's International Auction House holds numerous auctions during the year. They handle it all from the photography, shipping and to collecting the money.
  Morphy Auctions
  Lots of advertising, toys and antique holiday items have been sold on through this company. I've been a customer throughout the years and they always do a good job.
  
  OverStock
  Not a huge amount of collectibles or antiques, but you just might find a jewel or two on there and it would be worth considering for your own auction items.
  
  Pottery Auction
  Name a major pottery and there is a category for it here.
  
  Profiles in History
  Wonderful Hollywood memorabilia including movie props and autographs.
  
  R & R Auction
  R & R conducts a monthly auction offering approximately 2000 items of historical, Hollywood, art, literature, notables, sports and music autographs, memorabilia and ephemera.
  
  The company, solely owned by Bob Eaton, has been in business for over 20 years and is based in New Hampshire. Eaton originally started collecting autographed photos and has turned his hobby into a successful enterprise.
  
  Raynors' Historical Collectible Auctions
  Specializes in all aspects of Americana.
  
  Serious Toyz
  Toys, diecast and animation art are a few of the categories.
  
  T. Vennett-Smith
  An auction house in the UK dealing primarily with postcards, ephemera, and memorabilia. Find out about their upcoming auctions.