I like the sound of this!
A while ago I read this:
http://www.penguin.co.uk/static/cs/uk/0/minisites/happybirthdaypenguin/html/35.html
(which makes me want to read it's source Niall Ferguson's bestselling The Pity of War)
In there's an excellent description of how the various foreign ministries telegrammed each other in the build up to WW1 and what the various parties were trying to achieve.
I don't remember all the details, but there were big troop build-ups, particularly by Germany and Russia and I found it particularly interesting and enlightening to hear that once the politicians pulled the trigger, then the generals effectively cut comms and wouldn't respond to political directives.... it was too late, they were at war and they were going to do their job!
This idea of having variable unit upkeep made me think of the comms situation and how, before advanced comms, you could have a financial penalty for pulling out of a war too soon.
So, not only the buildup and preparedness of your forces impacts finances, but also yo-yo-ing from war to peace too rapidly. Maybe the penalty is on the first turn (or two) of war, but it forces a little consideration about declaration... perhaps there is no penalty if you are not the aggressor - you get a free transition to and from war if you are attacked, but your costs still escalate from the second turn (presuming your units weren't in a war ready state)
I would even say, given the new 1uphex, that you could apply readiness on a 'front' basis rather than individual units - so all adjacent units would consist a 'front' and be at the same state of readiness. Reinforcements or other movements could be added to or removed from the 'front'. Having many 'fronts' could also be costly....
Don't know if that all makes sense, it kinda came together as a concept as I was typing
