Ok since we need to get started some
where, some
when and some
how...
... I decided that "
right here", "
right now" and "
whatever comes out of this" are the best answers to these questions.

Now, the old system was very, very complex - as even things like tractive power and speedbonus were core items of the basic calculations. With the new, table-based speed bonus system, I hope we can get things easier than this.
...
BRAIN STORMING:So for the beginning we will ignore all these special & complex things like bonuses, etc. and just do it
simple.
Step 1: Calculate the max. income (vehicle fully loaded) per km(=tile) a vehicle can generate (according to the freight-types transport fee from the goods definition).
Step 2a: Calculate a balanced RunningCost for that. I think other paks do it this way, so might also try it: we could figure out a load percentage that marks the point above which a vehicle will be profitable (or will generate losses if below that).
Of course we have to consider the fact that most freight vehicles will drive empty on 50% of the way, while passenger and mail usually carry loads both ways.
Step 2b:
We also have to include some margin in 2a that will be able to pay all the required infrastructure (like roads, tracks, catenaries, bridges, tunnels, stations, etc.)
Step 3:
Purchasing price... I think that one is actually quite freely adjustable, but we could develop some kind of "guide line" balanced on net income of each vehicle - i.e. determining "how long" it should take until a vehicle pays itself from its own net income.
Open problems so far:
- solution for vehicles that only pull others but have no payload themselves (loco's, trucks)
- implementation of speed bonus
- ... probably several more - but I'm not going to do this all alone.

So, now...
YOUR ideas, comments and solutions are required...
EDIT:
I had another look at the old Excel sheet - and it seems that load percentages were also used as reference in pak128 (Pass. 75% and freight 48%). And I got quite a number of ideas from it - let's see how many I can get to work in my version.
