The French money system is made difficult to understand because there are two kinds of "money": "money of account," which is a kind of theoretical money which does not directly correspond to any coinage, and "money of exchange," which are the actual coins that change hands in the course of doing business.
The value of any particular coin (a concrete piece of metal) can always be expressed in terms of "money of account." The Sire de Gouberville in his journal (1550ís-60ís) mentions 32 different kinds of money, but he reduces most of his financial transactions to the three denominations used as "money of account": the denier, the sou (12 deniers make one sou), and the livre (20 sous make one livre). The ratio of 12:20:1 is a classical one that supposedly reflected the relatives values of copper:silver:gold. Anywhere the Romans went, there are traces of a money system that uses these proportions. (The English also used "money of account" where 12 pence = 1 shilling, 20 shillings = 1 pound sterling).
There are no actual coins for the money of account. Kings minted coins which could be assigned values in terms of money of account, and these values may fluctuate given such factors as inflation (a concept not well understood then).
A coin would usually be known by its picture or some other visual characteristic, not its monetary value. It did not have an actual value printed on it, as we commonly do. For example, if we applied this system to modern coinage, a modern dime might be called "a Roosevelt" and depending on the state of inflation or recession in the country might sometimes be worth 10 cents, sometimes 9, sometimes 12, etc.
The basic unit of coinage in France is the écu au soleil. It is the only gold coin that has been minted in France since 1484. Its value relative to the money of account has fluctuated throughout the century. Since 1574 it has remained stable at 3 livres to the écu, due to the monetary policies of Henri III.
The most common coins for daily transactions among the "menu peuple" are the blanc or dixaine, a 10 d coin, and the grand blanc or douzaine, a 12 d coin. They are made of a billon, copper/silver mix. There is also a silver teston, worth 10 s (120 d). The franc was a silver coin that used to be worth a livre, but none have been minted in our century. The term is still sometimes used to mean a livre.
There were lots of foreign coins in circulation as well and accounts were sometimes kept in them. Spanish coins are particularly popular in the west of France (i.e. where we are). I also imagine English coins would be popular here in Calais. Most of the foreign coins were high-value ones, worth much more than a livre.
Note that the multitude of coinages was further complicated during our time because there were at least three different kinds of mints operating in France. The Catholic League held most of the big cities and the old royal mints, and they made coins in the name of Charles X, their pretender to the throne (who had died in 1590 after 4 months, but was the only plausible candidate they had). Usually there was another town nearby making coins in the new royal mint for Henri IV. And there was a third group that wanted nothing to do with either party and was still making coins in the name of Henri III, who had died in 1589.
We use our own coinage in le Poulet Gauche, with values of a dernier and a sou. For an explanation of our use of money, see Rules of the House. Our coin dies are supplied to us by Claire Rutiser.
This century has seen an enormous rise in prices that has impoverished the agricultural and working class. The daily ration of bread for a manual laborer on an estate was 1.7 kilos a day (which provided 89% of the calories in a peasant diet). In 1500, a skilled artisan made about 4 sou per day, which would buy 15 kg of bread - about 8 daysí worth. That same artisan in 1594 made 10-15 sou per day (less in winter), and could buy about 9 kg of bread - about 4 daysí worth. An unskilled urban worker made 5-7 sou per day (about two day's bread), and an unskilled female made 3-4 sou per day (a day's bread). Agricultural day laborers were even worse off, a man earning 7-8 sou per day and a "woman of all work" only 3 sou, no matter what the skill. Womenís wages suffered especially sharply. In 1500 she made at least half of what a man did, and in our time some women laborers got no more than a single sou for a dayís work. Keep in mind that day laborers, especially agricultural ones, only worked when the weather was good, and often had no work for one- to two-thirds of the year.
Contracted laborers on an estate made less cash in return for a percentage of the crop. In 1500 that percentage was usually a tenth Ė by the end of the century is was about 1/15th. A servant in the house of a rural estate earned around 100 sous a year, a woman around 60 (some things never change). Such a laborer lived with the family, and got food, shelter, and usually a pair of shoes and a shirt or apron along with the wages.
It is hard to get the price of a "loaf of bread", given that the weight of such a thing might vary, but the daily ration of 1.7 kg (3.75 lb) of bread would cost about 2s 6d. In 1500, the common person ate pure wheat bread ("white"). By our time, that bread is much "blacker" -- about one-third rye, even near the Mediterranean.
A bushel of salt could cost between 3 and 18 sous, depending on taxes (salt smuggling was major activity). A bottle of wine could cost between 1 and 3 sous (wine was not actually sold in bottles; you brought your own to the wineseller who drew it off from the cask for you).
Montaigne in his travel journel (c.1580) quotes a good Swiss inn as charging 4 livres a night for a gentleman in the off-season. He mentions that a horse there cost a reasonable 40-50 écus.
For examples of prices, see excerpts from an original account book of the 16th century.