Dave and Northmn,
It's absolutely true that every source document is going to have some kind of bias in it, or it may be just that the person didn't know something that would have made things look differently to him or her.
I love these discussions as everyone can bring in a piece of the puzzle or a very interesting tidbit someone else may never have heard and it gives us more information to look back and perhaps get a better picture of what happened.
I was extremely interested to read about the cost of muskets vs rifles.
Back in the 1980's, the people in the gun shop at Colonial Williamsburg said that muskets and fowlers cost about 6 to 8 dollars and rifles cost 9 - 12 dollars for "common rifles" unless the rifle was very highly engraved, decorated and inlaid with semi precious or precious materials and was a special order for a truly rich person. They also said the average wage of an average person was about a dollar a month. I assumed they were talking about Spanish Milled Dollars because the time period was such that we would have been using them along with Pounds and some coinage from other countries as well. However, I don't know for certain if they meant Spanish Milled Dollars as I had a lot of other questions I was much more interested in at the time and didn't think to ask about the rate of exchange or coinage.
I've been thinking about Northmn's comment on how many casualties were taken by British light troops vs American Riflemen. I'm sure some of it would have been because our Riflemen were better shots, but I don't think that's the only reasons. I can think of a few important additional reasons.
As Northmn pointed out, Britain did not have a "hunting society" filled with average men during this time period. Hunting was usually the activity of the rich while the poor man poached. I think some of those successful poachers would have given our American Riflemen a run for their money for woodscraft and being sneaky , but certainly not all nor even the majority of them. Poachers also usually didn't have to contend with hostiles who would steal from or kill them and were often as good as woodcraft (or better) than American Riflemen. After all, the Native Americans taught woodscraft to European Colonists either directly or "through other means." When one goes hunting for deer, one has to be sneaky. When one goes hunting for deer in an area there are hostiles that are hunting the hunter, the hunter had to become pretty darn good to even survive. I have no original documentation to completely support this, but I'm pretty sure our American Riflemen were better at being sneaky and woodscraft then most British Light Infantrymen. As such, that would also account for more casualties of British Light Infantrymen because the Americans could use their strength in tactics.
I also believe the British weren't looking for just the Hessian Rifles, but the Hessians who knew how to shoot the rifles well. I don't know how many of the Hessian Jaegers were actually hunters in those years, but at least the core of them were. Many would not have been hunters in the exact same sense as ours were, but even if you worked for the noble who was going to shoot the game, you had to get him in the right spot and quietly enough so the nobleman could shoot. You also had to be a good enough shot if the Nobleman missed, that you "finished" the game for him (even when the Nobleman flat out missed by a mile) so the Nobleman could "claim his prize" and more importantly HIRE the Jaeger for more hunting parties in the future. That's what made them additionally valuable to the British as the Jaegers brought their hunting skills along with their skills at shooting.
There is also another thing we have to keep in mind about the British Light Troops and that is tactics. Scouts then as well as "point men" on patrols on the modern battlefield, often take a higher percentage of casualties than other infantrymen. If nothing else, scouts would often "spring" a trap laid for the forces on his side. If they opposing force was smart, they would allow the scout to get further in so the trap could be effectively sprung on the force following him, BUT it was in the American Rifleman's best interests to make sure they took out the scout. Sooner or later the opposing force runs out of experienced scouts that way and the patrols of opposing forces are not going to be nearly as effective. Light Infantry by design or happenstance also often wound up making first contact with the enemy. That alone would cause more casualties in their ranks. If one is attacking a good defensive position held by resolute troops with more or less equal weapons and plenty of ammo - and you don't have significant supporting arms, you normally have to have a 7 to 1 ratio of soldiers to ensure you will take that position. However, you must count on losing a bunch of soldiers doing it. The superb example of that was the Battle of Breed's (AKA Bunker) Hill where poorly trained militia men inflicted such grievous casualties on the British attackers until the militia ran out of ammo. It got to the point there that the British didn't really WANT to use more direct assaults on the Americans at Breed's Hill and normally in European Warfare would have flanked or used artillery or cavalry on the American position, but those weren't available. It also became a point of honor and more importantly for strategy, they couldn't accept a poorly trained militia would beat some of the finest infantrymen in the world. If the British Army was not feared, they could not be as effective.
Something I believe the British never really considered as well they aught, was that a new supply of replacement soldiers and supplies were not just across the English Channel as it was on the Continent. They also didn't look at the Rev War so much as a War like the Patriots did, but a rebellion that they expected to put down like recent earlier rebellions in what is now Scotland and Ireland.