I’d love to have the price be comparable to other trains in the game with similar capacity and speed, so around $1.5-2 million, same for the maintenance costs, just something that is balanced with the rest of the (default) vehicles. Real-life years would be cool as well, I always feel like cheating when I’m using these because of the zero cost.
Otherwise the models are brilliant! Really cool seeing the Dutch trains I travel with weekly. Have you considered doing dutch carriages (https://nl.wikipedia.org/wiki/Intercityrijtuig)? Goes well with this NS-reskin:
http://www.train-fever.com/forums/topic/class-186-nederlandse-spoorwegen/