@FeralRobots "The Day of the Jackal" was an insane commercial success as a book—multiple millions sold, at a time when that didn't normally happen in publishing—and movie budgets were an order of magnitude smaller in real terms, so less meddling by money men.
2001, from 1968, was a very expensive high budget movie of that era, made for $10.1M, or about $91M in today's terms.