The Galaxies I recall from the early 70's had only the 3 main tubes reynolds, low end components, and generally low quality workmanship. I'd say looking at the condition 100 is generous. Also, the value may be in the leather saddle, they came with a cheep thinnish leather, but that one may be a Brooks, its worth some if it is.
Edit I just saw it is a brooks, raise the value to 150.