According to a new study dug up by Secrecy News, modern-day spies -- at least the ones who get caught -- don't appear to be making much money.
The study (.pdf), conducted for the Defense Personnel Security Research Center based on its Espionage Database, concludes that "Two thirds of American spies since 1990 have volunteered. Since 1990, spying has not paid well: 80% of spies received no payment for espionage, and since 2000 it appears no one was paid.” (more)