I've been around a long time (71yrs.) I'm retired.I've been a studio owner, Record label owner and agency owner. I've owned a lot of guitars. I have'nt seen a real answer to the question of "why martin guitars are so expensive? One thing that always made martin stand out in the feild when I was doing some radio, and television in the 60's and 70's was the tonal quality. There was absoloutely no mistaking the martin sound, it stood alone. Gibson also had a sound
of it's own. I heard nothing that came close. I owned both. Each had distinguishing tones, I'm talking acoustics of which I'm very familiar with. Martin built on this reputation but did slip on build quality in the 70's to 80's. Yet you might pick up one that is up to tonal quality in those years. An example I still have a 1970 D-35 12 string with poor quality build. The neck collapsed on it. Why did I keep it? Any musician who came into my studio and picked it up said " what a great sounding guitar." I hope this helps answer the question. They built a reputation in my musical area on the distinguishing tone.