Velodyne HGS12-repair or replace?

I’ve got two Velodyne HGS12’s. One recently stopped playing after having it sent out to an official Velodyne repair center after about 5-6 months ago. Warranty is like 90 days on the repair. 

I’m trying to determine if I should send it back out again or sell both and finally move on. 

If I were to move on what subs should I consider? Can I find new subs out there that don’t cost $1000 each but are very good? I like nice clean bass and have usually been a fan of sealed subs as it always felt tighter and cleaner. 

One dealer mentioned REL, but haven’t listened to the yet. I see a lot of great reviews of SVS. I have heard one JL Audio ( can’t remember model) but it ran about $1500 and sounded pretty damn good. 

I I had a pair of HGS 18, replaced amps on both. Traded them in on a pair of JL Audio Fathoms at great expense. They are very good though. No problems yet, but :

I suspect that the amps in any powered subwoofer are prone to problems. 
A friend has a pair of SVS subs. Seem to be very good for the money 
I've had the same HGS-12 sub.  I was very surprised that with careful placement I was able to get excellent performance out of it. You may consider looking around at replacing the plate amp with an aftermarket.  I've not heard the REL's (great rep), but I've played with a few of the SVS and their performance was excellent for the buck.  
Good Luck
velodyne repairs those for not too painful of an expense.  i repaired my dd15 and its been great for years since.  yes there are better subs for cheaper these days but you wont even get close to the hgs for the few hundred that repair will cost.  At $800-1000 you can better the hgs.  
The HGS were great but every one died eventually or will....  i had one, should have had it repaired but bundled it with something i sold and that guy fixed it.

My Dads 10 died , sent it to this place in NJ and its been working great for over two years
EBC Electronics repairs them for $175.   That said I replaced my HGS-12 with a Rythmik 15hp and the difference is huge.  The Rythmik is in another league in terms of transparency and output capability.  It makes the a velodyne sound muddy and compressed.  
If its still under repair warrantee why not let them take another stab at it?

A little more than your budget but light years better than your short list. 

Not all subwoofer room optimization is the same.
Velodyn's first incarnation of their Automatic or Manual Room Optimization did a better job than the initial JL Audio F113 version and the REL Studio III was simply missing in action when I compared all three in home at the same time. 

Room correction / EQ are my first priorities when it comes to subs. That is by far the biggest contributor/detractor to sound quality, so I would pay attention to that when shopping around. 

I love my Hsu sub, immense, powerful, but I do my own EQ via miniDSP, so I save a ton of cash.