CNG and Agora is really all I know. I don't know which sites to trust and which not. I don't really feel confident enough to use ebay for anything pricey unless I spam this board for every coin I like, and no one wants that. Thanks
I've used Bertalomi ACR, heritage, Agora, Harlan J Berk catalogue and mobility auctions, pecunem, pegasus, nomosag, and cng. Cng is probably my favorite and most used. Harlan has high reserves on most of his coins. Pecunem throws in a fake every once in a while. You may get nailed by international transfer, credit, insurance, and/or bank fees by ACR. I've been wanting to use Spink, but haven't registered (I think they check references, but am not sure.) I believe Spink has been around the longest. Overall, imo, I think you'll get the best value in nomosag and cng Eauctions. Before bidding in any of them, be sure to check their terms and conditions for buyer's fees and shipping/insurance costs. I'll see you on the bidding field. Edit: use numisbids to keep track of upcoming catalogue and Eauctions. I recently used catawiki for a small purchase and don't recommend. It's essentially ebay, except they sneak in shipping fees after the bidding has closed. Edit 2: if you're looking for a particular piece, I use Ngccoin's auction results database to search for hammer prices and upcoming auctions, which provides a date, link, and auction house.
What iamTiberius said with some modifications. I don't recommend ACR Bertalomi because they have had a significant problem with fakes in the past and my personal experience trying to return one was a nightmare. They seem to be reducing the fakes but I'd wait if I were advising you and see if they have really fixed their business practices. Others are Roma Numismatics and Baldwins in London, Gorny & Mosch, Kunker, and Hess-Divo in Germany. Watch tooling in the German auctions. CNG is always a safe bet, easy to pay, good coins but also lots of competition due to that. I use SixBid to watch my auctions and sometime place bids if I can't participate live. It works well IME.
My favorite auction sites are (ancients) Kunker/Hess Divo/Baldwins/St. James/CNG/ Nomos/Solidus/Rauch/Roma/Lanz/Spink/Tkalec AG. also Pannonia Terra Numizmatika =Hungarian coins Numisma=Portuguese coins Cayon/Jesus Vico/Aureo&Calico=Spanish coins Sincona=Swiss Cantonal coins i Numis/CBG.fr/Gadboury=French coins Aste Bolaffi/Raineri/Nomisma=Italian coins Steve Album=Indian/Islamic coins John
Check out sixbid.com. That will give you most of the bigger auction sites. For me though its about ease of usability. Many of the dealers have truly horrible sites which are difficult to navigate. I do like sites who allow one to 'watch' various lots without bidding on them first. But then again there are sites I like but have serious flaws. One major auction house doesnt allow you to review any of your bids under your account, so you will have to keep a separate list. Anyway, there are many aspects which might affect whether you will use their site or not. You should check them all out, decide which ones are easy for you to use and then register with them. Like I said, sixbid will give you a darned good list of the biggest and best sites, and most are quite honorable, though unfortunately many European sites will not mention detractions such as smoothing or tooling.
