You are right. At all these serious auctions, coins are sold in perfect condition for a lot of money, but no one asks where they have been for 3000 years. Now I'm asking this question in relation to my coin
Many later ancient Roman coins (200 AD or later), can be purchased in very fine or extremely fine condition, for less than $150. And, many such coins have been professionally cleaned, to remove the toning. Therefore, the condition of the coin, and the cleanliness of the coin, do not indicate that the coin is fake, to me. However, I'm not expert enough, in this coin type, to know if the coin is authentic or fake. Sometimes, the edge of the coin, shows signs of casting or electrolysis, if the coin is a cast fake or electrolysis fake. Sometimes, the obverse and reverse show signs of casting, if the coin is a cast fake. The better the photos, and the clearer the photos, and the better the lighting shining on the coin, and the higher resolution the photos, the easier it is, to find signs of being a fake. However, I realize, that, not everyone has access to the best photography equipment.
There's really no such thing as condition being "too good to be genuine." But I don't think anyone can confidently determine authenticity based only on these photos (unless someone recognizes a match to a known fake). You can also compare to some genuine examples of the same type. Sometimes more context helps. (E.g., was it bought from a specific auction, at a tourist site in Turkey, etc.) In almost every case, where they've been is underground. Some have been above ground for longer -- that is, someone dug them up earlier, whether by chance or intentionally (e.g. with a metal detector). There are coins documented to have been in collections for c. 500 years, but anything beyond a few decades is the exception. The majority of coins appearing at auction (especially budget auctions) have been found much more recently with metal detectors. Cleaned. Dispersed, consigned, and auctioned. Then off to CoinTalk posts.
