for me, the chassis making process (using plexiglass) was an iterative process. first, I often measure slightly wrong, no matter how careful I am. when things have to fit tight and well, I always have to make a few adjustments from the 'paper model'.
second, what may work and fit - may not look quite as good as I wanted, so I need to move things around, reburn some new plastic (or paper; my trick was to use manilla office folders to dry-fit ideas first, see how well the spacing and aesthetics work out, and only commit to plastic once I think I'm ready for a real model). I can tweak the layout, try new things, make alternate front panels. then bring them all home with me that nite.
just CANNOT do that with mailorder remote work. you can't iterate, well. and its expensive.
even just using the machines can be informational. I learned some tricks that might not translate well to a remote person doing the cutting for you.
and finally, if I broke something and need to make a new panel for some emergency event or demo, having a shop that is local can make all the diff in the world.
fwiw, this is what I usually make - this style of box - when I'm there. its a bit 'industrial' and funky looking, but I have the process down, I can do the painting myself and the cost is VERY low for the plastic and even the time is not very long to get this done.
someone talked about just machining metal boxes, like the old LMB and BUD and whatever brand is current, these days. I grew up hand-working bakelite and plastic and metal boxes (radio shack style, etc) - and doing all the holes with hand drills, xtacto knives, reamers, files. I NEVER want to go back to those days again! ;( every box had dings or skips or 'drill walks' and had to be covered over or just looked like they were done by hand. and doing each one was so slow and time consuming. the laser cutter really was life-changing, in terms of my DIYs. note, I don't do this for a living, I don't make hundreds of boxes and I don't usually sell things, but I like things to look nice and if I'm trying to demo a concept, a clean looking build makes all the diff in the world.
so, yes, I need that $30k laser cutter to get this kind of work done. without it, I'm back using stone knives and bearskins, and I really hate the thought of that.