[abysmalpoptart]

if you ask me, this is the best way to calculate it:

if the next 2 levels of endurance are cheaper than your next house, get ONE level of endurance. if not, get the next house.

i did a comparison with a few people

level 16 endurance with a Ranch gets better trains than 12-13 endurance in a midlan house (or equal trains). might be worth it to get the end