When buying new commuter rolling stock to service the "challenging" Blue Mountains Line in the Sydney New South Wales commuter rail network, it does not pay to always go for the cheapest option. The South Koreans were 25% cheaper than local manufacturers but now it has been revealed that the cost of converting the tunnels and platforms to fit the new trains will far exceed the savings.
http://www.abc.net.au/news/2018-06-...face-blowout-to-make-fleet-fit-tracks/9844832
http://www.abc.net.au/news/2018-06-...face-blowout-to-make-fleet-fit-tracks/9844832