I agree. I have a similar US Machine Tools #1 mill I purchased from my employer. While it doesn't have as nice a paint job I paid less than 10% of the price the owner is asking for the Diamond mill. These mills were built for war production work. As such they use a lever for the X axis rather than a crank handle with gear reduction. They were made for repetitive production of identical parts. Moving the handle about 2 complete revolutions moves the table the entire traverse distance. To get accurate dimensions the table movement distance has to be setup with gauge blocks or standards. It's somewhat crude by later years standards, but it does get the job done. Having said that I find I use mine on a regular basis.
For that price it should come with a glass display case
The rack and pinion for the x axis would be awkward for hobby use in my opinion, I have a Diamond B-12 and couldn't envision dealing with a lever
It also cuts the travel by 2" according to the brochure: