I second DeGaulle, need to work on your coffee. That said, Gail says your grinder should work fine with pressurized basket, http://www.youtube.com/watch?v=eiAOpwfGiTU
Is the grind finer than a drip grind on the finest setting? You can compare to store bought drip coffee if not sure. If not, then probably need a new grinder. If yes, then thinking the pressurized portafilter isn't working correctly. If you acquired it second hand, it may have even been depressurized by the previous owner.
If the fault is in the grinder, I can vouch both a Capresso Infinity and a Baratza Encore will work fine with a pressurized basket. IMO you don't need to spend more than that. You will get better coffee if you do spend more though. If you had a proper espresso grinder, then you could also depressurize the portafilter for best results. Never used it, but would wager the Breville is worth the extra money now if you think you will upgrade your espresso machine down the road, e.g Gaggia Classic.