I've found out that I can make a lower-cost plan based on the metric system.
I personally work in metric, so would see no issue with that at all. Many machines today are, and if one still chooses to work in imperial measure they can easily convert...
how important is the look of the machine over the function?
The first thing that popped into my head when I read that was, "...form follows function..."
The "look" of something from a marketing perspective can often be important, however there are commodities (like tools) where function and ease of applied application to a given task weigh out most other aspects like aesthetics; which are actually a state of mind, and opinion...not something to be achieved perfectly for all viewers...
I know we'd all choose wood and iron for looks, but would anyone still be interested in a lower cost new alternative that looks like it came off the space station?
If you talking about something that is 3D printed from spot welding machines, I have seen some of that work, and it is really good and rather artful in nature as well. No matter the approach to means and materials, the final outcome has to work and be cost effective. As Will pointed out the better of the still existing machines are those of Miller Falls, and Boss. I look forward to you proto type.