A/V Receiver for 2.1 PC system

I live in a rectangular, longer-than-wide studio apartment, with my computer on the far end of the rectangle. I use my PC as a sound system for music (mostly jazz, classical -- rarely party music). I would like to get a smooth sound that projects across my apartment lengthwise. Can anyone recommend a soundcard, a/v receiver, speaker set? I currently have the Soundblaster x-fi elite pro, connected to logitech's z2300 2.1 speaker set. My current system sounds fine, but I've read so much about the musical wonders of a real receiver, that I'm curious to see what it's all about. I want to stick with 2.1 because of space constraint issues, so I don't think I'm willing to spend more than, say $150-$200 for the receiver -- I don't need a full 7.1 receiver.

Any suggestions? Is my current system sufficiently good that an upgrade to a receiver/speaker system wouldn't be worth my while?