Where Do All These Dealers At The Flea Market Get Coins?

The majority is from customers looking to sell or people who have no clue about coins selling to the flea market dealers.

The Morgan pros will have a more in-depth answer, but I would say probably because mintage was only 450,000 and that's not considering the survival rate. Try looking for an 1893-S and see what they go for just as road kill.

Availability of coins at the flea markets are pending where your flea market is located. Some are just regular coin dealers and actually have a coin or hobby store and find the amount of possible customers is much better at a place where possibly thousands walk by on one day. In such stores your sitting there waiting for a customer whereas at a flea market you could possibly find individuals that never considered a coin store. This is also true of other people at flea markets. For example at one I go to there is a Doctor that works in a clinic during the week. A barber that has a shop during the week. A plumbing person that also has a plumbing operation during the week.
Then too there are people that own a pawn shop and sell all kinds of merchandise broght in to their pawn shops during the week including coins.
One person I know that basically sells coins, comes from another state and in his area coins are no big thing so he can buy them from hobby type stores for practically a fraction of what he sells them for at a flea markets in big cities.
Then too there are many situations where people have inherited a coin collection, start selling it off at a flea market, find it is a decent buisness, start looking for people that have coins to sell.
Of course there are many situations where the merchandise was illigally obtained and is now being sold at flae markets. Two such flea markets were raided here a few weeks ago for all those illigal copies of movies and many not even released at the theaters yet.
I do know one coin dealer that owns a coin store and sells at a flea market on weekends. He said he does more buisness on one Sunday than all week in his store.

I know for a fact some flea market guys buy wholesale from coin shops.

Like everybody above said...Auctions, personal collections(they add up quick)flea markets, the more people you ask the more people will bring you stuff.
This works on so many levels...It's the if you build it, they will come.
I know a guy that opened an stamp and coin shop (coins were always second to stamps with him though)
He had his initial investment, and never sunk a dime of his own personal money into the business after the first three months.
On a good Sunday afternoon, he would get no less than 6 or so collections that came through the doors.
He would look through maybe half of the first book, flip through maybe one or two of the others. (briefly)
He would then ask...what were you looking to get for the collection? After a brief haggle session, they would sell the lot to him. After all, they just wanted to move it along.
On more than one occasion, after the deal was made, He would pull out maybe a half a dozen pieces out of the first album, set them aside and make the comment...Well that collection is paid for...then toss the rest of the collection off to the side for sorting later
If people know what you collect, you can't imagine what people will bring in.
Case in point...The above dealer, scored a stamp that sold for auction for 75k
I don't think he knew it until several years after he closed the shop.