I traveled in a roomette and a shared bunk on overnight trains in the US and Europe. One was worth the additional $420.

Source: Business Insider

Business Insider's reporter spent TK hours on a Nightjet sleeper train in a private cabin. Joey Hadden/Business InsiderI booked overnight trains in an Amtrak roomette and a Nightjet shared bunk cabin in Europe. The roomette was a 20-square-foot private space with two beds and a toilet for $500.