I could see doing two of the 1262W (2 or 8 ohm). Wired for 2 ohm and an iNuke 1000DSP for $299.
$112 in drivers, $300 in amp/sub management via DSP. Another $60 in MDF. $6 in terminal cups, $20 in paint and $20 vinyl veneer.
So call it $520 and a day in the garage. There is nothing commercially touching this south of $1500 IMO.