Maybe another way for Cesar to look at things is how much sound for how much you have to carry. Sure, you can get a bunch of cheaper boxes for the same money. But now you have to move them. If one top level box makes nearly the same amount of sound as 4 cheap ones, you only have to move one thing. And if you save up and get another later on, you still have less to move and much more sound.
And there is much more to it than "simple SPL and freq response".
While a pile of cheap boxes may make the same "noise" as 1 or 2 better subs, the SOUND QUALITY will never be as good as the better subs.
There is A LOT that does not show up on the "simple numbers" such as SPL and freq response.
But if you want to "look impressive", then by all means get a bunch of cheap boxes and pay the extra truck to carry them, the extra speaker cables needed, take longer to setup, more amplifiers, more AC power etc etc.
It all depends on "what you are looking for". What is important to some people does not mean a thing to others.