As for actual trains, they can be suprisingly affordable (to live in):
https://atrservices.com.au/product/sa-red-hen-416/ https://en.wikipedia.org/wiki/South_Australian_Railways_Redh...
and the freight rolling stock flatcars make great bridges (single or sectioned) with concrete pylons either end for farms - once the axles are shot they can go pretty damn cheap and the beds are good enough to roll a car or small truck over.
addendum: in case you miss fresh reply to old comment: https://news.ycombinator.com/item?id=41484529
