The cheapest way to expand a station.
(https://picload.org/image/rigdgclr/magdeburg.png)
Design: https://flic.kr/p/e4LNqo (https://flic.kr/p/e4LNqo)
Yes, it´s possible in every pakset I think: Look for the cheapest station (rails, road, air), place a short way and the station and you will have a cheap station extension. Only way to prevent is creating more real extensions, for every freight in every size at least one.
I don't want it to be prevented :D