Thinking about it, there may be cases when province or army level summary information on upkeep might be handy. Specifically, where you have peripheral province or area that you wonder if it is worth holding given the cost of the required garrison. The Holy Land for Catholics is the obvious in game example. The Falklands for the UK is the obvious real life example for Brits.
Yeah, thinking about it your right. Likewise, somtimes it would be nice to know how much a stack that is out counquring is costing me each turn, that way i can work out just how much more Income I need before I can affiord another army of a similar compostion.