that would cost you about 2k right there eithout a mobo lets do some estimates
2 7800GTX around 1200
x2 4800 around 800
thats 2k
and 2GB of ram around 300 dollars
so thats 2,300 dollars even without a mobo
lets see a mobo around 200 dollars
so thats 2,500 dollars
need a case, psu, dvd drives, hard drives
that comes to around 3k
need keyboard, mouse, speakers
3,200
need monitor
3,700
need some fans
3,800
with shipping aroud 4,000 dollars
i think i can buy a car with 4,000 dollars