Hot price on this Headset w/ Mic for Microsoft Xbox 360 at eForCity. You can get it for only $8.99 shipped. These sell for around $30. The sale price is currently 10.99, plus use coupon code: EFWS010422 to take $2.00 off. No shipping was charged.
Also, you can shop through Ebates and get 2.5% back plus $5.00 if you are new to Ebates. So you would be paying, after your Ebates rebates, $3.77. Sweet deal!
Note about Ebates: The cash back and bonus money you accumulate in your Ebates account gets sent to you via check or paypal about every 3 months.
Another option is the Plantronics Over the Ear Headset for $9.99 from Amazon (org $19.99). Plus ships free with Amazon Prime.