Manufacturing has usually paid higher than other jobs. Would have expected the same at SA. Costs of everything was lower. You posted that list of prices for component parts for the Krag. Compared with today's costs they were disgustingly cheap.
Comparing apples to oranges a Krag probably cost 15 days wages, a Remington 700 today cost probably 3 days wages.
My mother used to pay 10 and then 25 cents for my haircuts when I was a kid.