Behind the screens: how did I arrive at these numbers…. A long story…
-First I calculated the quarterly/seasonal/domain turn pay from the daily pay of 5 sp amounting to +/- 50 gp for a 1st level pc class.
-Then I multiplied it for higher level using a similar formula as xp cost: adding the previous level times X (See table 1)
X = 50 gp
Lvl1= X
Lvl2= lvl1+1X
Lvl3= lvl2+2X
Lvl4= lvl3+3X
NPC classes have the same challenge rating as a pc class of one level lower, thus they should have a similar cost. (See table 1)
Table 1. Rounded Quarterly/domain turn Pay of a Unit Consisting of 10 members
NPC-Class Pay in garrison
Level 1 200 gp
Level 2 500 gp
Level 3 1000 gp
Level 4 2000 gp
Level 5 3500 gp
Level 6 5500 gp
PC-Class Pay in garrison
Level 1 500 gp
Level 2 1000 gp
Level 3 2000 gp
Level 4 3500 gp
Level 5 5500 gp
Level 6 8000 gp
After reading the many reactions to my question regarding equipment upkeep and replacement, I concluded that 10% per quarter, making 40% per year was not too steep as I first thought. Consequently, I used the PHB price for equipment cost, with a seasonal/domain turn upkeep of 10%
I then calculated that for muster and yearly upkeep costs to be equal as stated in the BRCS equipment value of a member of the unit should be half the quarterly pay of a unit of 10 creatures.
X= Quarterly pay of 10 members
Y= the equipment value of a single member of the unit
X+10Y=4X+4Y 6Y=3X Y=1/2X
Concluding
the muster cost of unit of 10 creatures should be:
10 x PHB + Quarterly Pay (table 1)
A unit’s Garrisoned Upkeep Cost per quarter/domain turn is:
PHB + Quarterly Pay
A unit’s Active Upkeep Cost per quarter/domain turn is:
2 x Garrisoned Upkeep Cost (PHB + Quarterly Pay)
-PHB is the total cost of the Equipment in the Player Handbook that the Unit holds.
-The Quarterly Pay according to the level and class of the unit is shown below on table 1.
-Additionally, when designing units with equal Muster Cost and Yearly Garrisoned Upkeep Costs, as in the Birthright-Play-Test, use a PHB equipment value of half the unit’s Quarterly Pay.
These figures led to relatively expensive units when one takes one GB to represent a gp value of 2000. A unit of infantry consisting of 100 1st level warriors with 100 gp value of equipment would be 12000 gp of Muster and yearly upkeep cost, with a GB value of 2000 it would make a staggering 6 GB… It should be about one third… 2 GB of muster and yearly upkeep cost…
Some of you pointed out that the GB is highly abstract, and I agree. I thus divided the costs for regents by three by taking a GB value of roughly 6000 gp when it comes to fielding and supporting an army with the following rationale:
The aforementioned cost is the cost that any common individual would have to pay to equip and field a unit. However, regents are not common individuals, as they represent an organization or state apparatus, which receives all kinds of support from its followers. This support is represented by the Gold Bar; regents that want to exchange this support for his personal gain, can exchange one GB for roughly 2000 gp, which can thereafter be spent to the regents liking including on military units. However, when a regent directly spends his goldbars on military units these units are gained through the various support his/ or her followers provided to the state apparatus. Brave men serve out of Honour, Loyalty and Duty, farmers and guild members provide food and craftsmen work to provide and repair equipment. Consequently, when it comes to fielding and supporting an army a regent’s Gold Bar is worth as much as roughly 6000 gp in cash.
Amounting to the following unit prices in GB
10 1st level NPC class with roughly 100 gp of equipment: 0.2 GB
10 2nd level NPC class/ 1st level PC class with roughly 250 gp of equipment: 0.5 GB
10 3rd level NPC class/ 2nd level PC class with roughly 500 gp of equipment: 1 GB
10 4th level NPC class/ 3rd level PC class with roughly 1000 gp of equipment: 2 GB
10 5th level NPC class/ 4th level PC class with roughly 1750 gp of equipment: 3.5 GB
10 6th level NPC class/ 5th level PC class with roughly 2250 gp of equipment: 5.5 GB
10 7th level NPC class/ 6th level PC class with roughly 4000 gp of equipment: 8 GB
These prices led me to easily reconstruct the BRCS units for the same price in Gold bars, but with more information regarding their experience, equipment and numbers:
Archers: 100 1st level warriors, with roughly 100 gp of equipment 2 GB
Infantry: 100 1st level warriors, with roughly 100 gp of equipment 2 GB
Pikemen: 100 1st level warriors, with roughly 100 gp of equipment 2 GB
Seasoned Scout: 30 3rd Experts/ 2nd level fighters with roughly 500 gp of equipment 3GB Elite inf.: 80 2nd level warriors/ 1st level fighters with roughly 250 gp of equipment 4GB
Md. Cavalry: 40 3rd warriors/ 2nd level fighters with roughly 500 gp of equipment 4GB
Knights: 30 4th level warriors/ 3rd level fighters with roughly 1000 gp of equipment 6 GB