Astonishing inference fail
Price, value et al are not applicable to the reference. Let's step through this: a subwoofer will spend most of its useful life plodding along at, say, 20% of its potential, due to the nature of the program material it is being fed...much like a car cruising on the interstate. However, there are instances (e.g. transients) where the full potential of the sub will be required to accurately reproduce the recording at the desired level. Likewise, the car
is sometimes asked to yield its full potential, say, accelerating on an on-ramp or braking to avoid a collision.
A sub with sufficient headroom (power) will be able to achieve this maximization of its potential (ramp-up from 20% to 100%) more smoothly than one with limited headroom. The sub able to accomplish this smoothly will sound better doing so (less distortion, etc.). The car with sufficient headroom (power) will also be able to achieve its maximization more smoothly, yielding better performance and likely longevity of its components; much like the sub.
All of this was implicit in the analogy. I can't believe I had to type it out!