Once upon a time I went into an electronics store and overheard this, “You’ve said you’re after a cheap radio, so these models might be a bit of an overkill for you.”
The word overkill means more than is needed or wanted or necessary.
More examples:
– We need to be really careful about misleading prospective students who choose a degree that will either constitute academic overkill for jobs better suited to on-the-job training, or does not have the academic content normally expected of a degree (The Guardian).
– Pupils ‘suffering from exam overkill’. GCSE and A-Level students are suffering from persistent feelings of anxiety, stress and fear at the pressure of exams according to a survey by the Association of Teachers and Lecturers (The Guardian).
Confessions of the Linguistic Spy 