With a name like "collegeaudio"...maybe it would help to clarify where/how you're going to use it? Maybe your name is a red herring, but using a sub for, say, listening to music in a dorm room will lead to different advice than, say, playing music for a big party.
Sub-$200 budget doesn't leave much room; Dayton subs are a common suggestion, but for some purposes the ultra-cheap Monoprice subs might be OK.
Waiting for a better (more expensive) sub probably isn't bad advice, but the Monoprice subs are practically disposable and apparently sound...good enough for <$100 sub. They'd do to fill out the bass on small speakers and for a little bit of boom in a small space.