I've decided that a higher-quality $50 pair is a better choice if it lasts twice as long as one more in my usual price range, and perhaps better even if it's not that much more long-lived but much better in audio quality. I don't really like inside-the-ear, but it's all that I can make work for being able to toss in a backpack...
So: Recommendations. What reasonably-priced headphones would any of y'all suggest? The primary criteria are:
1. Good sound quality; any set of headphones that costs ten bucks certainly doesn't fit.
2. Durable to backpack abuse. This is the big one that's why I have to use inside-the-ear headphones; regular ones tend to break unless I can find a case for them. I need headphones small enough I can stash them in my backpack so I can listen to music between classes.