The following is based on my 20 years + of collecting
ancient coins and speaking with coin dealers (both those with and without bricks and mortar stores),
auction house employees, vendors at coin fairs and flea markets, swap meet and collectors' club
members, metal detectorists and of course fellow collectors. I have engaged, in person, with various of these people in at least 15 countries. However, I may have missed many things and this is only anecdotal.
A complicating factor to our understanding of this phenomenon is that there are many layers between finder and the end customer. (I am only speaking here of "recently" found coins - not those from old
collections.)
Most modern finds are made by metal detectorists. These detectorists will then sell these coins to someone else. Some may sell to a coin shop/coin dealer but by far most appear to sell to middle
men. This middle
man may be the one who exports the coins or there may be several middle
men involved first. Coins usually eventually reach a brick and mortar dealer or an
auction house. They are then sold to the customer.
Each layer, just like with the ancient spice trade or silk road, adds to the costs and, intentionally or otherwise, obscures the origin.
In my experience relationships, and luck, can
help you gain access further up the chain or learn more.
Some examples.
I
met with one of the bricks and mortar coin dealers that I knew when I lived in
Vienna roughly once a week for five years. We chatted about everything. I sometimes helped him with IDs and references. Over that time period I learned a
bit about
his business. He bought from old
collections and from new
collections, from local detectorists and ones who came in from a few hundred kilometers away - both from
Austria and nearby countries. He worked with some middlemen who brought coins from detectorists or groups of detectorists from further away. Sometimes people came from abroad to
Vienna with coins and made the round of the stores trying to sell. I was there through several of
his buyer transactions but was politely kicked out for some - usually because of coin values not source.
I belonged to a few local collectors group that
met and swapped, traded, bought and sold coins. Through these I
met, and bought from, around a half-dozen detectorists - in other words direct from the finder. Some told me generally where their coins came from - e.g. "farms around town X" - a few told me exactly where they came from (they knew I
had no metal detector and was no threat to their find spots, plus many
had exclusive relationships with the farm owners). One printed off a photo from
google earth and circled the exact
field. Sadly I have only about a dozen or two coins with this degree of knowledge.
Some online dealers used to group their uncleaned coins by country of origin. I knew some of these dealers and trusted that they actually sourced their coins from that country. But that was no absolute guarantee that the coins originated from there. They could have been brought into that country from elsewhere. However, looking over large sample revealed in many cases an excellent match to documented finds.
On the other hand, some stories can be
complete fabrications. I have seen many flea-bay dealers
selling coins they claim are from
Britain or the Netherlands that anyone with any experience can tell come from the Balkans or the Middle East - not many
provincial SC issues from
Antioch or Latin Kingdom
Byzantine trachys are found in
England!
Anyway, enough late-in-the-day rambling. I
hope my experiences
help somewhat.
SC