I have never been thrilled with SE4's maintenance cost methodology. It's been a minor annoyance for me. I even e-mailed MM with some ideas about it a week ago.(Since Aaron's pretty good at responding and I haven't yet got an answer I take that as a resounding "Bug-Off!". LOL!)
I basically asked if maintenance costs could be figured as a percent of the build costs of each indivdual component and such and each item had its own script line for us to set the percentage cost for that item. I think it would be way better then the current everything costs X% or nothing deal.
I also asked if we could get a line in settings or the race files for each race that set its maintenance percent costs off the base.( We 'kinda' have that now, but, as you note, it's a little annoying.)
Oh well, I'll now go back to hanging out and waiting for the next patch like everyone else.