EW wrote: A 1000W logo does not equal 1000W output.
I bet you a dollar you could get that amp to put out 1000w of power. Granted it may require an 18v power source, a 1khz signal and it will only play for .10 seconds at 30% THD, but I'm sure it could do it!
A reputable amp company will have "birth certificates" with their amps stating how much power it will actually produce with what voltage and at what THD. My old MTX 2300x was rated at 150W x 2 at 4ohms, 20-20k with <0.1%THD, but it actually put out 201W x 2.
Good companies will have under rated amps that cost more. Crappy companies will have over rated amps that cost less.
*edit* Remember this. Size matters when it comes to amps and subs. Large amps shells help disipate heat better which means longer life.