Um, guys, he probably doesn't want or need that kind of power. There are a whole lot of people that don't care about having a system that is heard down the block and simply want accurate sound to be heard only inside the car. Huge power, even if you keep the volume down puts a strain on the car's electrical system. There's much more to the cost of the sub and amp setup than just the suba nd the amp when you get to a certain power output. You then have to start thinking about how to support the current consumption of the amp. Many people don't want to go to that length to add a small sub to their stereo.
For a modestly powered single 10 there are a ton of amps that fit that price and power range. JL 500/1 and Zapco 500.1 are hard to go wrong with. PG Xenon 400.1 and 600.1, MTX TA-4501, -3401 and -2301, Memphis 16-PRD500.1 and 16-MCD500 all fall in your budget (easily) and desired power range.