*@EdJohnston. Your question was about figures in summary. Here are a few points about this. 
 #Yes, the number of victims is important in an article about political repression. Therefore, the number (or a range of numbers) should be provided in the introduction. 
 #The numbers of people "killed" and the number of people "who died as a result of Communist policies" are different. The second number is significantly greater: it is more than 60 million (rather than 20 million) in the Soviet Union alone according to The Guinness Book of Records. 
 #I did not see any estimates of the number of people killed by all Communist regimes except "Black book", which qualifies as a secondary RS written by a group of European historians. It tells exactly this: "100 million people killed by all Communist regimes". They note that the number is approximate, which also should be noted in the introduction. If there are any other secondary RS that tell "N million people killed by all Communist regimes", they must be also used to obtain a range of numbers. 
 #As a side note to others, it is grossly inappropriate to discuss sanctions at article talk pages. If you think that sanctions are needed, please go to appropriate administrative noticeboards and report your concerns there.