been reading this thread. i am a foreigner and have never heard of many brands which are present here in the philippines. some of them are c7 , lightning labs, v12, kinetic etc. i have been into car audio for a while and have used many flee market products as well as good products. some flee market brands i used are Solid audio , sound magus , vtrek etc and some good brands include jl audio, digital designs, orions , cv , jbl, pioneer etc.
let me keep this conversation simple

SQ- sound quality : i would stay away from flee brands. invest in high quality products and you Do get what you pay for

SPL- if loud is what you want, you can look into flee market. you might get a 3000rms amp for x3 price less of a high brand amp. and IT will do the rated power with higher distrotion level.. but in Spl system, its all about watts! nothing about sound quality!!.

to use a high brand product or a flee market product is totally up to you, major role lies in the power, install and the box built.
if i am given a choice, i would say
1) high brand Headunit (pioneer,alpine,kenwood)
2) high brand speakers
3) flee market amplifiers
4) high brand subwoofer (sq) or flee market subwoofer (spl)

btw i will be making a new thread regarding these brands... do have a look.
thanks