I don't know how good of a surround sound headset you are going to get for $100. The really good ones are $250 and up. I've heard the sound quality for Tritton Ax Pro's are really good but have heard that Tritton's don't last very long. Maybe somebody here can vouch for them, I have Astro A40's. The Tritton AX Pro's are listed at $167 on Amazon http://www.amazon.com/Xbox-360-Preci.../dp/B0017IUFAE
Tritton's are less expensive then the Astro A40's and the high end turtle beach surround sound headsets.