I have Xetec Gravity 4G-600 MK2 4 Channel Amplifier for sale. The price is $150 plus shipping. XETEC is a great German brand with excellent sound quality.

Here are the specs:
4 x 110W @ 4 ohms (13.8V - 1% THD)
4 x 180W @ 2 ohms (13.8V - 1% THD)
2 x 380W @ 4 ohms bridge (13.8V - 1% THD)
Top Control
11" x 11" x 3"
Highpass (15-200 Hz, disengageable)
Lowpass (15-200 Hz, disengageable) for all channels