This is a single subwoofer system package that I put together using Asylum Car Audio 12" subwoofer,  a prefabricated ported enclosure, a CFAB1500.1 rated for 1000 watt RMS in this single subwoofer application, and a 4g Wiring kit. 

Here is a quick breakdown of each component:

$249.99 Asylum Car Audio 12" Subwoofer: 600watt RMS dual 4 ohm voice coil 
$99.99 Prefab Asylum 12" ported enclosure
$299.99 Asylum Car Audio CFAB1500.1 1000 watt RMS @ 2 ohm amplifier with bass knob
$99.99 4awg #FAM copper wiring kit with RCA cable and speaker wire. 

$750 total package value