$500 for a REAL amplifier is a steal. I have had Precison Power (back when they were still the REAL PP), Phoenix Gold, MMats,Memphis, Kicker, MTX, Orion, and they all cost substansially more than $500 (but you get what you pay for). Most amps on the market nowadays spend more money on advertising than research and development, and anyone can print a sticker saying 3000 watts. If it weighs less than 10 lbs, you can bet your paycheck that they sold you a POS.
For my money, Kicker and RF are the two best amps you can buy without having to sell your first born. They put out ALOT more power than they say they do (unlike your friends BOSS 3000 watt amp that barely makes his 10" sub move lol), and they are built to last. If you love music, spend your money on amps and speakers, and then have someone who KNOWS what they are doing install it. You can have the best equipment in the world, but if dumb and dumber install it you'll be lucky if it just sounds like crap. If you aren't lucky, they'll install something wrong and burn up your car and your stereo.
Remember, you get what you pay for. If it's worth doing, it's worth doing right. You'll thank me in the end!