I have been searching for a decent pair of below $100 in-ear headphones for traveling and use with my MP3 players.
Based on recommendations from several postings over at Head Fi, I bought a pair of Head Direct HiFiMan REO headphones. These come with several different types and sizes of buds, which can fit pretty much any sized ear canal. I found them a very comfortable fit.
The phones have a flat, neutral response without exaggerated highs or boomy bass. They sell for $79/pair and ship quickly from NYC. Got mine in 2 days.
http://www.head-direct.com/product_detail.php?p=38NB