I can't comment on the relative contents of the courses. But the different prices seem to come down to uni policy. LSE prices each course according to a perceived (very high) market value. Cambridge prices each degree according to a (highish) market value, with the exception of the three courses it highlights. I presume you have to add another £10k ish for the UCL course living costs?
I can confirm that £14k for the Cam MPhil in IR is realistic and allows you to live a reasonable student lifestyle.