Bazooka sucks.
Price sounds high.
I bought an 8" amplified tube four years ago for like $200 (online w/free shipping) and I installed it myself. POS never worked right but by the time I realized it wasn't my fault I couldn't return it.
I believe Bazooka has a forum and they also posted the same issue (bumps & thumps after you turn off your vehicle).
I've literally heard good things from an Infinity sub hooked up to an Accord stock radio.
I love bass.