Conversation so far:
When was J. Paul Getty's grandson kidnapped?
July 10th 1973
Who kidnapped J. Paul Getty's grandson?
'Ndrangheta
How old was J. Paul Getty's grandson when he was kidnapped?
16
Where did they take J. Paul Getty's grandson to?

Question: What was the ransom amount?
Self-contained rewrite: What was the ransom amount for J. Paul Getty's grandson