Very specific needs

[judasmachine]

I was wondering if you guys could point me to a cheap (sub $20) but good headphone for an LG AX 380 Wave. It's 2.5mm, and why I need just the one ear piece is the only time I use the mp3 function is when I'm mountain biking, but I still need to hear ppl yell at me as they come up from behind, or around a blind corner.