For similar price you could get the
BIC F12 ($198-$184 on buy.com)
Specifications
Design: Front-firing 12-inch, 475-watt peak powered subwoofer
Frequency Response: 25Hz - 200Hz
Sensitivity: 90dB
Drivers: 12-inch injection molded woofer with heavy duty surround
Magnetic Shielding: Yes
Gold-Plated Terminals:Yes
Recommended Power: Built-in Amplifier Power: 475 watts Dynamic Peak, 150 watts RMS continuous
Impedance: 8 ohms
Dimensions: 21 x 19 x 22 inches (HxWxD)
Weight: 42.70 pounds each
Warranty: 5 years parts and labor
or two of the $100 budget
12" subs from MonoPrice
Specifications
Speaker Type: 12" High Performance Powered Subwoofer
Driver: 12" Reinforced
Amplifier Power Output: 150 Watts RMS, 200 Watts Peak
Frequency Response: 30 Hz - 250 Hz
Lowpass Crossover: Adjustable from 50 Hz - 150 Hz
Functions: Power (On/Off)
Inputs: High Level (speaker), Line (RCA)
Dimensions (H x W x D): 17" x 17.25" x 17.5"
Review:
http://www.soundandvisionmag.com/article/review-monoprice-msub-a122-subwoofer?page=0,2