History of Space Exploration: Chapter 10, Exercise 1 — Possible Solution
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ANSWER
The reusable-vehicles article says reusability reduces cost by eliminating
per-flight manufacturing, but the benefit can be diminished by recovery and
refurbishment, and reusable stages carry extra weight. It gives limited
quantitative evidence, and the SpaceX article gives no per-launch cost.
Chapter 7 showed a reusable Shuttle at $450 million per launch (2011).

BETTER STATEMENT
"Reuse of first stages is now routine, but the sources do not quantify the
saving."