Calculating the Price
I tend to shy away from discussion of the price of ancient coins - while the price is relevant, even primary, in defining which coins I can afford, it isn't the most important factor in my enjoyment of the hobby. Prices for ancient coins cover a full range from <$1 (or even worthless) to priceless. There are collectable coins for any price point. Our ancient ancestors appear to have recognized the future need to support collectors at multiple price points, and introduced mis-strikes, weak-strikes, bankers marks, graffiti, varying degrees of rarity, varied aging conditions for coins to develop patina - all of which leave many options to choose from.
Should this coin be worth more or less than average for coins of this type? Here's an example where being a bit off-center and a die issue with cupid's head not fully defined, doesn't detract much on this particular coin. All elements visible, good style, good flan, nice dark toning, a full 4g flan with good silver, provenance from a very reputable dealer, a coin with interesting historical relevance, an unhappy, pointy-toothed, long nosed dolphin - overall many other positive qualities that outweigh the negative.
L. Lucretius Trio, AR Denarius, Rome, 76-72 BC
Obv: Laureate bust of Neptune right; trident over shoulder; numeral (L == 50) above
Rev: Infant Genius riding dolphin right; L•LVCRETI TRIO in two lines in exergue
Size: 4.00g, 18mm
Ref: Crawford 390/2; Sydenham 784.
This coin dates somewhere between 76 and 72 BC in competing estimates from Crawford (76 BC), Hersch-Walker (74 BC), Harlan (72 BC). This was the time of the third and final war with Mithridates VI of Pontus, the period post-Social War and post the civil wars of Sulla and Cinna.
An Expanding Republic
The republic was expanding. Gaius Scribonianus Curio, consul in 76 BC, afterward his consulship as proconsul in Macedonia conquered the Dardani and Moesians. Curio had some interesting tactics for dealing with unrest in his legions:
"When the consul Gaius Curio was campaigning near Dyrrhachium in the war against the Dardani, and one of the five legions, having mutinied, had refused service and declared it would not follow his rash leadership on a difficult and dangerous enterprise, he led out four legions in arms and ordered them to take their stand in the ranks with weapons drawn, as if in battle. Then he commanded the mutinous legion to advance without arms, and forced its members to strip for work and cut straw under the eyes of armed guards. The following day, in like manner, he compelled them to strip and dig ditches, and by no entreaties of the legion could he be induced to renounce his purpose of withdrawing its standards, abolishing its name, and distributing its members to fill out other legions." - Sextus Julius Frontinus, Stratagems, VI.1.43
Ultimately, he was successful and awarded a triumph in Rome
"The Illyrians, who had borne aid to the Macedonians, we conquered on that same occasion through Lucius Ancius, a praetor, and we received them, with King Gentius, in capitulation. Curio, a proconsul, subjugated the Dardanians and Moesiacians and was the first commander of Romans to penetrate all the way to the Danube." - Festus, Breviarium, 370 AD, 7.5
The Lucretia gens was one of the most ancient in Rome. The second wife of Numa Pompilius, second King of Rome, was named Lucretia. Another Lucretia of the same name and family was raped at the hands of Sextus Tarquinius which led to her suicide, and caused the monarchy to be overthrown and the Republic established. Her father, Spurius Lucretius Triciptinus, as one of the first consuls in 509 BC. The other consul was Lucius Junius Brutus, ancestor of the EID MAR Brutus. This coin may refer to an ancestor of the moneyer, C. Lucretius Gallus, who in 181 BC was duumvir navalis, one of two men responsible for managing the Roman fleet, and commanded the fleet against Perseus of Macedon.
Ancient coins are always a trade-off of factors: what is available, patina, condition, weight, strike, metal, centering, color, price...would I purchase this one for $1500 or this one for $3000 (probably not). I am pleased to own this imperfect coin (27.7g, 24mm) at the right price. Although it has a blotchy mahogany patina, exposing some bare metal, the surface quite nice in hand, a well preserved portrait, the aegis - a rarer feature - more visible than in the photo:
Trajan, 98-117 AD, Æ Sestertius,,struck circa 106-111 AD.
Obv: Laureate head right, drapery on left shoulder with aegis
Rev: Ceres, holding wheat ears and torch, standing over modius
Ref: RIC II 480 var. (no aegis)
A side view is helpful to appreciate the scale of this coin, which stands up on it's side quite easily.
Top 10 Pricing Factors
Here is my view on top 10 factors contributing to overall price (with an attempt to put it in priority order from biggest impact to least):
Popularity: one of the larger factors, the more well known a coin the higher the price. Demand a bigger factor in ancient pricing than supply in my view. Contrast with Rarity and Special Interest at end of list. Another face of popularity: who shows up and the auction and how much they want one. Two motivated bidders can change dramatically to price of a give coin - after all each coin ancient coin is in some way unique.
Metal: ancient coins were struck with a wide range of metal sources and debased to varying degrees, higher grade metal and a full weight flan generally adds to the price. Not surprisingly gold coins are in a different price range than bronze.
Size: the bigger the coin the bigger the price - while there are certainly exceptions - a tetradrachm or a sestertius or the largest Ptolemaic bronze will come with higher prices. Let's not even talk about dodecadrachms. The larger coins are more impressive in hand, have large canvasses for the engravers work...
Condition: from very worn with little of the original design remaining (good) to perfectly preserved from day of strike (Fleur de Coin or FDC). Various types of damage can affect an ancient coins value. Modern damage, for me, is the category that has the greatest negative impact on coin - I try to avoid these.
minting process e.g. flan crack, over-strike, double-strike, die-clash, misshaped flan, clogged die, brockage, off-flan elements, small flan, mis-strike
ancient use e.g. bankers marks, graffiti, scratches, countermarks
aging e.g. pitting, encrustations, crystallization, corrosion
modern damage e.g. harsh chemical or mechanical cleaning, scratches, tooling
Patina: the aged surface of the metal, more even surfaces with pleasing color are generally more desirable.
Strike: many possibilities with hand-struck ancients for off-center or weakly struck to perfectly centered and boldly struck.
Artistry/Style: die makers varied in their skill and range from crude engraving to artistic masterpieces, well designed and more complex scenes bring higher prices.
Provenance: Who owned the coin, and how far back is the documentation on the coin? Coins from famous collections, with long histories, and documented in publications and reference books, generate much higher prices.
Historic or Numismatic Significance: perhaps hard to separate from popularity in it's impact on price, coins from pivotal historical moment or which are the critical evidence in our understanding history or numismatics, have higher prices than those form quiet and unknown periods or which do not contribute to understanding the coins, where, why and how they were made and used in ancient time.
Rarity: one of the lesser factors in price, how many actually minted or surviving? many vary rare provincial coins (with < 10 known) are also very affordable. Far outweighed by popularity (or demand in supply/demand terms).
Special Interest: it is worth noting that any of the "negative" factors in a coins condition can become highly prized specialty collector item e.g. an interesting countermark, graffiti, mis-strike.
One of the questions routinely asked: are coins an investment?
Any asset could be considered an investment, and there are many groups/companies offering coins as investment (most often, US Coins or gold/silver bullion).
The Price Trend: In general I don't think coins keep up with inflation. Looking at all prices (US dollars excluding auction fees and shipping) for Crawford 287/1 between 2000 and 2023 in ACSearch
(For one anecdote see: https://www.sullacoins.com/post/my-investment-thesis)
Anonymous, 115-114 BC, AR Denarius, Rome mint
Obv: Helmeted head of Roma right wearing a winged Corinthian helmet, with curls on her left shoulder; X (mark of value) behind, border of dots
Rev: Roma, wearing Corinthian helmet, seated right on pile of shields and a helmet beside, holding spear in left hand, birds in flight to upper left and right; to lower right, she-wolf standing right, head left, suckling the twins Romulus and Remus.
Size: 3.8g, 18.5 mm
Ref: Crawford 287/1
Not as simple as it looks:
The same graph will not be the same for all coins or coin categories
Quality of coins sold could be changing
Perhaps the "outliers in high price" are going up?
My Purchasing Trend: The price I've paid for a Roman Republican denarius is going up (price in US dollars inclusive of shipping and auction fees).
Not as simple as it looks: I am generally drifting towards more unusual coins in better condition
The Supply Trend: The number of coins available in internet venues seems to be going up (number of coins offered per for sale each year).
Not as simple as it looks: there are likely other factors
Vendors joining internet venues & ACSearch
Lower quality coins coming to auction
Same coins reselling more frequently
Quality of coins seems to be decreasing
Calculating the Price
Going back to the question of "how to calculate price" - it takes some experience with a given coin type to get a feel for the reproducible price range based on the many contributing factors. Without knowing any given coin - just looking at it - you can easily be multiple orders of magnitude off (+ or -) in guessing price. What looks like a very poorly preserved coin for some types, could be an outstanding example and the other way around. Browsing past sales of the coin type you are interested in and looking at market averages is the best tool to quickly estimate "what am I willing to pay". The photo of the coin is not enough to gauge price, and it is worth paying attention to other available information like weight, size, provenance, et.c.]
P.S. While we are on the topic of price - here's are two useful links on the subject of coins and taxes: