You puts yer money down, and you gets what you pay for..
There is no substitue for quality, and quality has a price.. That being said, just remember that there is a limit to quality, and paying more for something that doesn't exist is just a waste of your hard earned rubles..
Yes, there are some inexpensive subs on the market, but they are just that.. At best, they have to be played at very low volume, in a very small room.. You would not want to combine them with high end gear.. What would be the point.. You have to match quality with quality, or your sound will suffer.. Would you buy a nice 4 x 4, and then shop for skinny little street tires ?
Save up for the real thing.. Don't ruin your sound with a bargin sub.. It's not worth the time or effort.. Believe me, for I have been there.. Mine is now in the garage, with the lawn mower and paint cans.. (where it belongs)


LFE ! The rest is just details..