Sorry for the delay in replying to these: have been preoccupied recently! My aim is to make the figures as close to reality as I can, and, if the constraints in the game differ from reality, alter those constraints to make them approximate reality as closely as possible.
I was hoping to obtain realistic information about the relative running and purchase costs of different types of rail vehicles (and other related matters) from somebody I know who works in transport, but he has been rather too busy in the event to procure them. What I really need to know, if anyone can find it out, are things like the comparative running and purchase costs of diesel, steam and electric railway locomotives, the differences between the running and purchase costs of large and small locomotives, the difference in running and purchase costs between different sorts of carriages, etc.. Once I have an idea how major factors affect the prices, I can extrapolate for individual vehicles. The same would apply to the differentials between rail and road, sea and air, etc..
The reason why I want these things, at least, to be realistic, at least in relative differential, is that those differentials in cost are the primary drivers of choice as to which vehicles to use in which cases, and appropriate vehicle choice is one of the important elements of Simutrans-Experimental. What I am aiming for is people making decisions in the light of realistic economic constraints, so that they do not need to calculate mathematically what will work in the Simutrans world, but can make the decisions as if they were making them for a real transport network, without having to think about how Simutrans is different to reality any more than necessary. For me, at least, every time I think in the game, "If this was real, I would do X, but in Simutrans, the best thing to do is Y", the game becomes less fun.
So, the challenge is: where does one find this information on the realistic relative costings? Does anyone know (or know where to find) information as to how much more that a steam locomotive costs to run per month and per mile than a diesel locomotive, or how much more expensive that it is to buy a luxury coach than an urban 'bus? All thoughts greatly appreciated!