China does not have any thing cheaper than india (food items) even in main land china. When that transported from there to Nepal for 5000KM calculate how expensive it will be in Nepal. Only thing china can supply in nepal is other non food items that too will be quite difficult when we use only through tibet. Currently most of chinese stuff is transported to Nepal from Colkata (sea route) (I am guessing here as Guanzhou (manufacturing hub in china is in south east of china (it is more south than Nepal)).

Do you add Madesi people in your 27 Million?