1
Jean Elsen Auctions
http://www.elsen.be/index.aspx
More info
Famous auctioneer of mostly ancients and world coins. Also publishes lists of coins for sale. Offers books and prices realized on-line. Brussels Belgium.
2
icollector.com
http://www.icollector.com/
More info
Live auctions of all collectible types around the world. Links or host many coin auctions. Locations in Canada, New York & Washington. Nice resource!