What is the rationale behind the high cost of crossbowmen?
According to Covenants page 18, crossbowmen cost 9 pence a day each, or 9 pounds a year. According to the price list on page 71, you can hire a ships's captain for 5 pounds a year, or man-at-arms for 2 pounds a year. 8 pounds buys board and lodging for a nobleman for a year. To me, the cost of crossbowmen seems too high. (The cost of Veteran Fighters, at 1 pound a year, seems a little bit low, though.)
Probably a typo. In Lord of Men, page 108, lists what mercenaries get while on campaign:
Knights (mercenary heavy cav): 1 shilling
Sergeants (mercenary medium cav): 4 pence
Infantry & archers: 2 pence
These are prices for the standing army created by Richard the Lionheart for his final confrontation with the frenchie king, so no levies involved, only full time mercenaries. Levies would not get paid, I guess.
So the 9 pence of the crossbowmen sounds too much. The 1 pence for the veteran fighters might be low, but they are not in a state of constant warfare, so it might be considered normal. I would put both veteran infantry and crossbowmen at 2 shillings/day.
It's because that's what the crossbowmen, whom clause 51 of the Magna Carta demanded be sent from England, were being paid ninepence a day by King John in 1215. It was as close as I could get to a "going rate" in 1220. If I recall correctly. I do recall the source was an article called "Crossbows for the King" by David S Bachrach, so you could check it to see if its a typo.
Remember: the longbow has not been widely adapted yet. The crossbow is -the- weapon for garrisoning castles. You don't need a lot of them.
It is worth noting that these are trained mercanaries with their own arms and armour.
If you supply weapons and armour, and train them yourself out of the local serfs, you'd end up paying no more than the cost of any lost harvest... Same as any other levy.
I've purchased the article "Crossbows for the King: The Crossbow during the Reigns of John and Henry III of England" by David S. Bachrach in Technology and Culture, Volume 45, Nr 1, 2004. I haven't got to read it thoroughly yet, but the only reference to wages I can find, is in the following paragraph (emphasis mine):
If the listed wage in Covenants of nine pence a day is due to an error, this could be a possible source. But, of course, you could have it from another source. (The article seems to be a very interesting read though, even if it doesn't clear up this issue.) I can't see that the translation of the Magna Carta at the British Library mentions wages either.
I see the difficulty in getting good data on real wages 800 years ago. According to the article "Wages in Late Twelfth- and Early Thirteenth-Century England" by Paul Latimer in The Haskins Society Journal, 1997: Studies in Medieval History, Volume 9, 1997, p 201-202:
The article gives further references to examples of balistarii involved in the making and repairing of crossbows getting paid at 4,5d., 7d. and 9d. per day.
Other sources confirm that crossbowmen in the 13th century was seen as extremely valuable soldiers, and got higher wages and more acclaim than other soldiers. This was also a period of heavy inflation, with costs for food and wages rising. I think I'll have to take this issue up with the rest of the troupe to decide.
This all reminds me of that hillarious scene from Monty Python and the Holy grail:
King of Swamp Castle: Did you kill all those guards?
Sir Lancelot: Um... oh, yes! Sorry.
King of Swamp Castle: They cost fifty pounds each!
Sir Lancelot: Well, the thing is, I thought your son was a lady.
King of Swamp Castle: Well, I can understand that.
Anyway, I agree that a crossbowman, being paid more than a knight, seems strange. All crossbows, according to Lords of Men, are Expensive weapons, and that means some amount of extra expenditure for the covenant. Also, in Lords of Men, on page 104, it says that a combat group of knights costs 15 pounds, infantry and archers costs 2 pounds and so on. These are mercenaries, and it's what the covenant would have to pay for extra hired soldiers. So hired mercenary knights costs less than a permanent guard of crossbowmen. Strange indeed.
So I would say that crossbowmen costs about the same as, say, veteran soldiers, but covenant would have to pay for the maintainance of Expensive weapons, which crossbows are.