The Revel B15 and B15a subwoofers are, hands down stunningly spectacular subs. If you can pickup a used one, by all means, they are worth every penny. I own a B15 and can tell you that I have never, ever been itching to upgrade that sub.
The new Revels subs that are forthcoming are going to be up there as far as pricing and will top out at $10,000 with the Rhythm 2 that pairs with the Ultima2 Line. I believe that that model that would be on line with the former B15 series will be starting at around $4,000. Given that you can likely get a used B15 or 15a for somewhere around $1,500 at the low end to $2,500 you are probably going to get more 'value' used at this point.
It certainly appears that the new Revel subs have really taken things yet again to a new level; so as anything in the audiophile realm, you will need to put a value tag on all that to see what makes sense to you personally.
Theo
The new Revels subs that are forthcoming are going to be up there as far as pricing and will top out at $10,000 with the Rhythm 2 that pairs with the Ultima2 Line. I believe that that model that would be on line with the former B15 series will be starting at around $4,000. Given that you can likely get a used B15 or 15a for somewhere around $1,500 at the low end to $2,500 you are probably going to get more 'value' used at this point.
It certainly appears that the new Revel subs have really taken things yet again to a new level; so as anything in the audiophile realm, you will need to put a value tag on all that to see what makes sense to you personally.
Theo