Alternatively I remember when I was a kid my grandparents would spend several weeks in a holiday let that had a coin operated meter for the electric, we had to keep feeding it coins to keep getting power, surely they could do the same thing these days.

like OpenTTD being a nice “rip off” of roller coaster tycoon

Sorry not sure if I'm reading that correctly, but how is OpenTTD a rip off of Roller Coster Tycoon, it's based on Transport tycoon a game made by the same developer as Roller Coaster Tycoon, released before Roller Coster Tycoon.

It's paid (one off $15 I think), but has a two week trial but I've been using Nine for a few years now, pretty happy with it.