no what i am said is:
if you want an all-in-one type solution (headset and mic) then go ahead and look at those usb headsets. however realize that once you start getting up around $100 there are far better things available.
even a low end pair of studio headphones will sound much better than mid to high end usb powered headsets. i just mentioned the model i personally use. if you also needed a mic you would have to use a clip on or desk mic with this though.
as far as using the integrated soundcard, this is because of your budget. the headset i recommended is about $100 if you get a very good deal on it (i paid $180 retail). also if you have a good integrated soundcard you might not need a slot card. however if you do not have integrated or want a soundcard then you do have the option to get a sub $30 card and pick a lower end of headphones.
i was listing my opinion on what i would do. since you are a different person with your own opinion just look at what i said and see if it is right for you. some people prefer the ease of use with a headset (with mic), some people like the 7.1 style headsets (with mic) yet others like to use better equipment. i'm just giving you ideas on what you could do with that money.