I don't know how everyone feels about this site, but this looks like a pretty good deal, no idea on the quality of the headset though.
http://www.meritline.com/komodo-360-0868-livechat-headset-mic-xbox-360---p-50126.aspx?source=nl100809&hq_e=el&hq_m=2021946&hq_l=51&hq_v=6834a793d8