CDN40 is about USD30, right?
That's an awkward price point for headsets, as they tend to go up to about $20, where the cheapies end, and then jump to $40 where the high-end ones begin.
I'm assuming that by headset, you mean headphones and a mic.
This is a good one:
http://www.newegg.com/Product/Product.asp?Item=N82E16826106935Sennheiser is a good brand, though this is about as cheap as they get:
http://www.newegg.com/Product/Product.asp?Item=N82E16826106347The problem is that a lot of the cheaper headsets save their money in the microphone. Good quality headphones can be had for $25-30, so the headsets that cost in the $30 range have fine headphones, but crappy mics and booms. Crappy mics will pick up breath noise, and crappy booms start falling out of position after a couple of weeks.
Also, unless you have a pretty powerful system, you want to stay away from the headsets that use USB, they eat up CPU time and require drivers.