Velodyne DD15 is a badass sub, I had a 12 and a 10 and they are subterranean and clean... that DD15 was like $2500-$3000 back then which is like $5000 today... I say fix it, there ain't no sub out now at $500 or even $1500 that can compare, that sub goes down to at least 16Hz with authority...
I say fix it, I just fixed the amp and redid the surround foam on a 10 year JL Audio Fathom 112 myself, thing sounds great and I picked it up broken for free from a client