What good is a power meter for a noob?
I'm the noob -- in just the past few months I've started to go out longer and try harder, and I've gotten a lot faster (though I am still very slow). Power numbers are ubiquitous in training and biking discussion, so naturally I'm curious to see how I measure up. But even a used power meter would be more expensive than my bike by far.
I guess the question is: at what point does a power meter become useful? (Or a real head unit for that matter.) Who doesn't need a power meter?