I would shell out the extra money, for a Rythmik FV12 for $499 with FLAT frequency response, respectable output, and servo distortion control.
http://www.rythmikaudio.com/FV12_specs.html
Although I would prefer to see an independent source of testing, that looks like a much, much better frequency response. I agree with you; I think I would save my money until I could afford the Rythmik FV12 or something better, instead of getting that BIC. But I can understand people not wanting to do that, for various possible reasons.
Of course, it is significantly more expensive than the BIC, and so it ought to be significantly better.
Or I would do what I have actually done, and keep my eye out for used subwoofers. I have picked up 3 used SVS subwoofers over the years, all in mint or near mint condition, all for less than half retail price. Interestingly, one cannot generally find that much off the bottom of the line units, which makes them a less good deal on the used market than higher models. My "cheap" SVS is a Plus model; I plan on passing it on to my brother when he visits, and I expect he will be very happy with it.
Anyway, the Rythmik FV12 is too much to keep the recommendation within budget, and so I personally would just forgo a subwoofer until there was more money for it. I have owned a cheap subwoofer long ago, and although it added some thump, it was not a good value, as it was not satisfying in the long run. Things that one buys, only to replace, are usually very bad values and cause one to spend more money in the long run than if one had just saved up for something decent in the first place.
