Hi i'm looking to upgrade my speakers currently i have:

creative inspire 6.1 6700's, i'm only using 5 speakers, i feel like a change and my mate wants them off me for an alright price, what are my choices? I can't afford top end ones however. My budget is £100 and under.

I'm using a xfi extreme music with it also

Creative I-Trigue 5.1 5600?

Logitech X530 5.1 Speakers?

I haven't got a clue when it comes to speakers. Or is it not worth an upgrade?