It's easy to sell coins; it's a lot harder to replace them as they sell with coins priced right, so you can mark them up to retail.
I can help you. The secret is simple, but the execution is sometimes almost impossible. The goal is to find hoards of coins, cleaned or uncleaned.
If they are uncleaned and unsearched, you have a better chance of finding some really great coins.
Cleaned coins will typically have been cherrypicked, if not carefully searched, and you won't find those incredible rarities typically in the hoard. But on the other hand, you won't have to clean the coins and you can see ahead of time whether a coin is attributable or not.
Attribution adds value to the coin. It's actually the main thing you do to earn your markup.
It's a real artform to attribute a coin. You can find out more about that in my blogs on this site.
Sorting is the first job, after you've committed to a wholesale bulk lot. You're looking for the great-looking coins in the bunch. At this point, you probably don't know a shekel from a hemiobol or a drachm, but you'll soon learn.
Attribution simply means to identify the coin -- is there a portrait of a ruler on the obverse (front)? Is there a goddess or a galley or some funny runic marks on the reverse (back)? What date is it? What is its condition, rarity and what other things are going on on that coin?
Attribution of Roman coins is relatively easy, if you learn to recognize the portraits of the Roman rulers of the Republic and the Empire (after Julius Caesar the Roman world was Imperial, which is a theme echoed in Star Wars).
Attribution of Greek, Phoenician, Ptolomaic, Byzantine, Celtic and Eastern coins are not going to be so easy, because they tended to not have the same simplistic device of the local ruler on the front.
So, you've sorted the coins ... After you've sorted your wholesale bulk lot, you'll want to find out more about the better looking coins first, and the trashy looking ones last, although some of those can be quite rare and pricey.
After attribution comes pricing. You can easily determine the prices of coins based on similar coin prices commonly found on whatever site on which you plan to market them.
Next is knowing how to ship and insure coins, how to get them through customs, etc., because collectible coins are taxed when they pass through customs, regardless of country.
You've sold some coins out of your hoard. Now, believe it or not, here comes the hard part: you have to replace them with another wholesale bulk lot; easier said than done.
Lot of 10 Cleaned Roman Coins @ $10 each, $100.00
Lot of 10 Cleaned Greek Coins @ $50 each, $500.00
Lot of 10 Cleaned Judaic Coins @ $50 each, $500.00
Lot of 10 Cleaned Medieval Byzantine Coins @ $50 each, $500.00
Lot of 10 Cleaned Widow's Mite Coins @ $10 each, $100.00
Lot of 10 Cleaned Ptolomaic Egypt Coins @ $30 each, $300.00