the ONLY thing I use headphones for is listening to music in transit. on my bike sometimes, on an airplane, on BART, maybe on a hike. in any other situation, that's what speakers are for. I personally think headphones in general are the least pleasant way to listen to music. I can't imagine paying more than $20 for any headphones. if I so desperately need to disassociate from the world, I'll stay at home and blast PiL Metal Box. if I'm in public, well, I chose to be there so I'll interact with the world.
it's just not worth it to me. on a bike? you're never gonna get your money's worth out of a pair of high end "In Ear Monitors." Jesus, even typing that phrase makes me feel like a prick! on a plane? is it so hard to read a book or take a pill? besides, consider the source. 99% of the time, these headphones are gonna be used to listen to MP3s, right? you've already compromised the sound quality right there!
sure, if you're also using these headphones for some serious work or listening in a good environment, go crazy. but the OP's query was in regards to on-bike listening. spending good money to listen to crap music on a crap format in a crap environment just seems like a waste to me.
you sir, do not know wha you're talking about.