The randomized controlled trial produces a clash of ethical principles with the need for informed consent (autonomy) in conflict with the principles of beneficence and justice. Informed consent is one of the major rate‐limiting factors of recruitment and this delays the discovery of life‐saving treatments indirectly. Whilst supporting the concept of non‐exploitation we wish to challenge the prevailing dogma by asking the awkward question ‘what is the price of autonomy?’. Using breast cancer as an example we have developed a decision model with explicit assumptions allowing numerical values to be fed into a mathematical equation, which calculates the cost in lives. With conservative assumptions we estimate that the price of autonomy is 2500 lives over a 10‐year period in the United Kingdom alone. We issue the challenge to health policy makers and ethicists to survey public opinion to determine the value placed on autonomy in the war against cancer.