That said just giving your speakers more power doesn't mean they'll get louder. You'll inevitably run into the limitations of the enclosure, drivers' thermal power handling, and driver's mechanical power handling. These are real things and you may not YET be sensitive to them, but chances are that you're already hearing them even on 30 to 60 watt peaks in the 100hz to 300hz range especially. Getting speakers with better cabinets, and better drivers, and better crossover design, can get you better results, even if power remains a constant. And of course more efficient speakers are normally a sensible idea, so as to reduce wasted current turned into heat energy.
My advice is this: don't spend much money trying to wring the most out of cheap speakers. It's fun, but pretty much a waste of time. Get better speakers - it's way funner.