That budget isn't going to buy you much of a crisp sound with heavy bass.
I find most PC speakers are crap.
Only crisp PC speakers i have used were creative t40 but bass is punchy rather than heavy.
Go to a Hi-Fi store and buy an amp with 2 decent speakers and enjoy.
I have a pioneer amp and speakers hooked up to PC and it cost me £150 which i guess would be around $200 as you get stuff cheaper then UK.