One thing that has been said is you are going to get some cancellation in your bass response, this will manifest itself as dips in the frequency range where the sub will be fighting its own reflection so-to-speak. Since you are already at the $1100+ budget range, you might thing about getting two $600 subs like two Hsu VTF2, Rythmik FV12 subs, or Outlaw LFM-1 Plus subs. These companies would probably be up for giving you a small discount for buying duals if you ask. This will help smooth out the frequency response. Without room correction, you are going to be facing peaks and dips, and two subs will go a long way to fighting a FR that looks like a roller coaster. You may want to add some form of equalization in the future for a flat frequency response. You could also just get one of these less expensive subs now and get another one if you find a lumpy FR. Even one of these $600 will pound pretty hard in a 1500 cubic foot room. By the way, whatever sub you get, in order to determine how uneven the frequency response is, you are really going to want an SPL meter. I strongly recommend getting one, especially since you are doing sound production.
One more thing, I don't know if you know about this already, but one fun web based music music tool is
Audiotool. Click on that blue button in the upper right hand corner that says "launch app" and start making some tunes (or alternatively, just
click here). I don't know how much experience you have with softsynths, but you may want to go through the tutorials if you don't know how to set up the modules. Anyway, its a pretty great synthesizer and sequencer, considering its a free web based app! If you are just getting started making electronic music, I know some other great free softsynths, let me know if you are interested. I would
strongly recommend getting to grips with the simple synths before throwing down hundreds of dollars for something like Reason or Omnisphere.