On the price side, Cambridge has 3x the population of segovia, and the same distance. Similarly, London has 3x the population of Madrid. My quick Google says there's 6 million jobs in London and 3 million in Madrid. My napkin math says that the demand for the Cambridge route is likely to be 2x if not 3x the Madrid route.
Youve also missed over the fact that the Cambridge train is more like 45 minutes than 60.
There are also up to 12 trains an hour from Cambridge to London (Liverpool Street, Kings Cross, St Pancras), this is basically as often as some city metros's. Time taken varies between 54 minutes and 1:29 hr.
Youve also missed over the fact that the Cambridge train is more like 45 minutes than 60.