warpdrv has a good deal there ... and is a good seller.
if you plan to upgrade your budget, i would recommend the PC13 Ultra 1399+99 shipping.
otherwise, get warpdrv's sub
Thanks mike....
Ultimately everyone here has given great advise, its a huge room... For good quality effortless bass, 2 subs would be the way to go...
I'm running Dual SVS Plus/2's in my 8200 cu ft room, and Its more then enough, but a single Plus would be a good amount of bass in your large room, but if after a while you when you really start to get more into bass, and start pushing it, it won't cut the mustard. Dual plus's would be far better, or like abboudc's suggestion to get dual 25-31PCi would fit into your budget.
There are alot of budget subs around, the one I have for sale is a good quality sub, but it offers great asthetics.... If that is not necessary, then there are lots of other alternatives.... that might be more budget oriented...
There is nothing wrong with getting a single sub, and then later down the line add a second...