Are subs worth the price for music?

My current speakers are Vandersteen 3A's. I consider them to have a good, solid low end. Specs say 26hz, -3db, if I remember. That's lower than most any music. I'm considering adding a vandy sub, possibly two to the system. My question is, for strictly music, are subs even worth while...$$$......if so, why? What could I expect that's different and/or better than what I'm already hearing..............No experience with subs and music, so forgive the lame question for those of you who already use them.
Subs can be great for music, though agree proper set up is crucial. I had great success with Vandersteen 3A and Genesis sub some years ago...
I concur with soix  Once I finally got a pair of Velodyne HGS-10s integrated with my KEF LS50s, it opened up the sound so large orchestrations that had been the downfall of the LS50s are presented convincingly.  Adding the subs changed the entire experience.  I use a Velodyne SMS-1 bass manager to low-pass the subs at 50 Hz with a 24 dB slope to minimize overlap; the SMS-1 also provides acoustic room correction.  The LS50s are driven by an Ayre VX-5 Twenty amp, the HGS-10s by the SE outputs of a KX-5 Twenty preamp.
Well, maybe the Speaker can go down to 26 Hz,

but your source, amp, and all PCs, ICs, and SCs will need to carry that clean and low of a signal to get you that 26 Hz to your ear. Also, If the bass player/musician, or the music you listen to is not playing below 26 Hz, then you are not missing out on anything. 
O/w, 26 is just a number.

That said, I have some Dynaudio Contour floorstanding speakers that go down 32-35Hz. But I still felt like I was missing something, missing the “presence” of the band and the music.

I’m not an HT guy, but I found that using just one quality sub, placed b/w my Dynaudios for music listening, gave me that extra LFE that allows me to feel like I am more present “in the room/venue” with the band.

I use a Zu Audio Undertone, a sealed sub that down to 14 Hz or so. That is more than I need, but the sub is so good that it has pretty seamless integration. Besides, I’m only integrating LFEs, which are more omnidirectional.

So, I would makes sure all your gear upstream is good enough to produce LFEs down to 26 Hz and you are listening to music frequently enough that goes past 26 Hz. If that is the case, and you are still unsatisfied, then check out some high quality subs that are robust under 26 Hz, like the Zu Audio sub.

Low frequencies are part of natural ambience that's everywhere, and subs bring that stuff to the room...not simply the low notes, although clearly that's a good thing, but the sense of reality that's part of live sound. I use 2 RELs with a small tube amp driving efficient speakers, and it sounds like real music.
Interesting arguments for subs folks. I'm going to put at least one, possibly two on my short list. I'm guessing that the Vandy subs might work the best with my 3A's, but as has been pointed out, there are others that seem to work very well also.

Saw a pair of 2wq's on ebay not long ago for a decent price. I'll take another look. Used might be a good way to go, less expensive and if I'm not happy with them I could probably resell and get most of my money back.

Don't know any other a-philes personally except a buddy down south, so I don't get much opportunity to hear other systems............Nearest high end shops are about 80-100 miles away, Baltimore and DC, which makes them inconvenient unless I want to commit a day to "shopping". Haven't done that for a while, might be a fun way to spend a day..........and $$$.

My listening room is 14x23x7'8"..........not huge, but big enough for decent audio. In your experiences is that "enough" room for a sub, subs?.........I also don't have usable corners for placement. Three of the four corners have open doorways. The fourth is occupied by a 500 pound aquarium...............not the easiest thing to move.............All the above might make proper setup for subs problematic, maybe impossible, I don't know.

Your experiences are extremely helpful and appreciated, thanks.