Limit your search to finding a good pair of bookshelf speakers, and then gradually add on as your budget allows. Forget about a 5.1 package if you're limited to $250, since the ones in that price range generally sound horrible.

Most of the floorstanding speakers I've heard in the sub-$1,000 price range have issues with cabinet resonance and compromised imaging resolution. In my listenings, I found that bookshelf speakers provide much better performance value. All that you sacrifice is the lower bass response, which you can make up with a subwoofer.