sound is a variable, even in the lower frequencies. and as a variable, persons have the right to express their personal impressions of the recreation of said variable by the subject of our scrutiny, in this case, a $300 subwoofer. some like anechoic tuned subwoofers, i do not. some like the specific character of some loudspeakers with passive crossovers, where i do not. for my personal taste, if it does not offer full control in the form of active crossovers (dsp), i dont want it. this preference makes the price range quite a bit higher than the medium that stores offer, but is it overpriced? in my case, no, it is not. because, like sound, my budget is a variable that i have complete control over, just like my dsp operated sound system. to others, my budget might be ridiculous, but that does not affect me or my purchasing decisions, nor do i care. what is overpriced to one person, is cheap crap to another person, again, more variables and differences in opinion.
have i heard the difference in subwoofers? yes i have, and it is possible to hear the difference... you just have to know what manufacturers make superior products.