Source Land Economy

The Economy of the Source Lands is part of the Source Lands Setting.

Coinage
From the Pre-Imperial Era and until the late Colonial Era, coins were the preferred means of paying for expenses for those who had them available in most of the civilized regions of the Source Lands.

Value of Coins
It wasn't until the Westerland Empire made a specific ruling on the exact value of a minted Imperial Coin, and by extension, any coin of similar weight and purity, but these rules soon faded out of existence. The issue with these rulings was that they were not essentially backed by anything.

Income and Expenses, basics
As a rule of thumb, when living outside the comfort of the home, a person can generally (assuming average prices apply) survive on 1 Gold Piece per day, which covers all the basic necessities of hygiene, laundry, basic mending of clothing, sustenance and lodging.
 * In addition to that, a farming house-hold, on average, generates 1 GP worth of excess goods per day. This is in addition to generating what is necessary for them to improve their farm marginally by next year and producing food and basic necessities for themselves, so as not to need to buy them, and assuming they barter goods for what ever they can't produce and have already paid taxes in goods, so basically, a farming house-hold on average quite simply makes a flat profit of 365 GP per year, in addition to already having seen their farm improve and being well cared for.
 * As for a laborer, after food and lodging and general expenses have been subtracted, the laborer has made a profit of 1 GP per day. Note that this is per laborer - not per house-hold. This means laborers families make more money than farmers, but have to buy many things, though it becomes easier if multiple individuals in the house-hold work, which is often made possible by living in laborer housing, where an "Old Lady" (typically a grandmother of someone) holds the house, and both parties of a married couple, including the children that are old enough, work for a living, often making very reasonable amounts of money - however, laborers are forced to set aside vast quantities of this money toward retirement, as they can't count on living off their land as they grow too old to toil.
 * Soldiers, whether part time or not, tend to earn money in a more organized fashion. A professional soldier will receive 10 copper pieces or so in petty-cash, while his wife receives a weekly payout of 10 GP, half of which is often kept for a retirement fund that she receives if the soldier dies, or he receives once he retires from service - the fact that the Lord keeps half of the soldier's wages, means that the soldier is heavily dis-incentivized to desert or disobey orders to the point of dismissal. Soldiers are usually forced to have their families live in specific places, for security reasons. The families often live in the baileys, acting somewhat as hostages to ensure that the Soldier remains loyal to the place he serves, but their housing is paid for, and soldiers are generally not taxed, making the soldier's life (and that of his family) a comfortable life, but not at all luxurious.
 * An average artisan charges roughly 1 GP per hour of work, but there are many exceptions to this, and quite frankly, Guilds tend to dictate the rates based on quantity of products and quality thereof, not actual hours spent working. As a result, most Artisans tend to be happy to produce many items of average quality that there are high demands for - horse-shoes, pottery products and woven baskets etc., though such items do not fetch a particularly high price, artisans make somewhere between 1 and 5 Gold pieces per day, after they've paid their guild rates, their assistants, their clerks and their suppliers as well as paid their personal expenses.

Plying a Trade
Players with no marketable skills can earn 1 GP per day, with no prior arrangements made, meaning any player who can find even unskilled employment, assuming the local settlement can pay average wages, can basically pay for their costs of living and barely scrape by, though players with marketable skills (toolsets, specific skills etc.) can earn one GP per Proficiency. If their proficiency bonus is 2 they make 2 Gold Pieces per day, etc.

Charging for Mercenary Work
It would seem like a fair comparison to compare mercenary work to the work of a regular soldier. Mercenary work is generally charged by the day worked, with a starting charge (per mercenary) of one tenth of the mercenary's equipment's worth and then 1 GP per day for general expenses (feed and rations), a charge of 1 GP per 8 hours traveled, 1 GP per 8 hours camped, 1-10 GP per enemy fought and hazard pay for the assignment as a whole, ranging from nothing to as much as the mercenaries could negotiate. If special skills are required to complete the job, an extra 10 GP is charged per special skill, and an extra 2 GP per each use of said skill.
 * Unless otherwise specified by a contract, mercenaries keep the spoils of war, but such spoils, unless actual valuables, tend to sell for ~50% of the new price.
 * Mercenaries might have to require a certain amount up front to cover expenses.

Buildings
Derived directly from the "cost of living" in the Player's Handbook of D&D 5e, if we assume that the cost of living is a fair guide on expenses toward a home, we can assume that roughly one third of a character's expenses go directly toward their home, one third to food and one third to general expenses.

One-Person/Couple House
Essentially a shack or a cottage or perhaps a shared duplex of some sort, these very small homes are affordable and reasonable enough for those without children or elderly parents to care for, and are rare bought, though commonly rented for some time. Such lodgings would not at all be expensive to build, costing only around 730 GP to buy from new and being much less expensive if older or built by the inhabitants themselves.

A single-family house
Typically where farm-hands, living on the land of relatives in the country would live, or a place where laborers might live in a settlement, the cost of a small single-family house with no capacity for holding animals or any significant storage or production capability, then we can assume that the price to buy a brand new house of such a type would be 3,965 GP - which obviously is significantly reduced if the house is older or if the inhabitants build the house themselves.

Multi-family house
Typically the homestead of the main branch of a larger family of farmers or a large house or compound in a settlement where several families acting as one house-hold can live together, across two to four generations of a family, with plenty of storage, plenty of work space and plenty of production capability to ply trades and work on various projects from home. Such a house, from new, would cost 7,300 GP, and again, of course this would be cheaper if the home was old or if the home was build by the inhabitants themselves.
 * Of comparative price, you would find a Town-House (typical artisans lodgings) in the bailey.
 * The small single-family homes that Soldier-families and the most trusted servants and officials typically inhabit, within the baileys, are also of a comparative price, though obviously, these are usually owned by the aristocrats that employ the aforementioned, and merely extended as lodgings.

Manor
A compound in the bailey or a proper manor in the country-side, these sprawling and impressive homes practically function as landmarks and often quite pleasant to behold. They are built to last, and of such significance that they are not often sold, and when they are, it is the talk of the entire region. The price for such an impressive structure would be in the range of 14,600 GP from new and are not often for sale and cannot merely be build by the inhabitants, but if one has obtained permission to build such a structure, it is almost to be assumed that one can obtain some sort of discounted labor to assist with the project.

Tower-House
The smallest of the clearly aristocratic venues, a tower-house is a fortified military structure, typically of significant importance to both the owner and to those that live near the structure, depending on it for protection. While not uncommon to build a Tower-House from the bottom and up, tower-houses often spring from existing manors that are upgraded or expanded, making the immediate project cheaper, but building a tower-house obviously requires the presence of a mason and many skilled laborers, with the tower-hose often staring out as a wooden construction that slowly evolves into a proper stone structure, and they are very costly, at an estimated price of 36,500 GP, and will almost never be for sale and cannot be build by own means.

Larger Structures
The prices just keep increasing... But beyond the tower-house it becomes difficult to say exactly what something would cost.

Taxation
In a medieval society, it is virtually impossible to even imagine paying income taxes. Rather than that, property taxes are essentially where it is at. Obviously, not everyone pays these though.

Farmers and Taxes
Farmers pay their taxes according to what they are growing/cultivating/rearing - these taxes are paid in the form of that which they actually produce, in a measure depending on how much land they have to work on. This is an important part right here - farmers essentially pay the same taxes whether they use their land or not, which is why you can assume that a farmer, if it can be avoided, wouldn't be caught dead without fully utilizing his lands, as he will be taxed to the fullest extent of all lands that he owns.

Different Values
Now, a pasture that has been declared in use for rearing cattle will require a smaller payout of actual cattle than a pasture dedicated to rearing goats, and even more so if the right gender is given up as taxes - a bull is worth more than a cow, and a cow is worth more than several goats, but the taxes are also lowered and raised to incentivize and dis-incentivize certain productions.

Laborers and Taxes
As a rule of thumb, laborers simply don't pay taxes at all. It is really quite simple - laborers can't afford to pay taxes, because they can't simply pay the taxes with part of their products, so there would be no laborers if they were charged taxes similar to those of a farmer.