if u cant afford new speakers and youve got a midi system of some sort why not connect your pc up to it. It may not be perfect but its far far better than pc speakers.

Oh and something ive found really helpful aswell is to hook up yur decks to the pc so that you can play everthing out of the same speakers (your production & a vinyl) you can then compare it all an then you'll notice how shite your last 2 months worth of work sounds compared to the latest Gas release or whatever

I'm not saying your stuff is shite by the way, but when I done that i realised how weak as fck my stuff was. :?