The militaria business has a sacred task, it is the only way that the experiences of the average soldier can be preserved for the future outside of museums.
Museums are great, but it is often necessary to have hands on experience for many reasons.
That does tend to bring out the worst in people that might otherwise be very mediocre. Dealers MUST make money, and 'lifers' like me have to make a living, if they are to continue serving collectors, local historical societies, large museums, and our history in general. So some markup is necessary. I will quit before I become one of them. But they are around us everywhere.