Personnally, I don’t complain about the price I’ve paid for Train Fever. If I remember well, I’ve paid 19.99€, which is quite reasonable enough given all the work that has already been done by UG to develop the game and the number of hours I’ve spent on TF.
I’ve paid marginally more for CS (27€), but I consider that both games give very good value for the money spent, especially compared with the crapy 70€ AAA blockbusters that big companies (EA, Ubisoft, …) are releasing nowadays.
I don’t regret any Euro cent I’ve spent on TF 😉