the setup i used to have was golden, i sold it with my old car, and for all the parts, subs box amp wiring kit etc. i spent about 300 which is your price range.
I had 2 10" Cerwin Vega Stealth subs which at the time i got both from crutchfield for about 130 shipped. They were 400 watt peak, 250 rms. The speakers were mounted in a bandpass box, which i payed about 50 for, and a jensen 500 watt amp which put out 250 per channel cost about 150, wiring kit cost about 20 bucks.
my friend spent a fortune on his and he had a 1000 watt 12 inch speaker with a 800 watt amp and my set up hit harder then his. rattled walls in the house but if kept low sounded perfect.
a good set up for a small budget.
As I was walking up the stairs, I met a man who wasn't there. He wasn't there again today, I wish I wish he'd go away.