PCBRITE

Hi I want to ask if anyone have experience with similar problem 
Ordering a cheap pcb is not a problem even if I use just one piece and throw away other pieces price is still nice 
but what about projects where I have to use BGA packages (as lot of modern chips don't have leaded alternative) 
Is here any cheap manufacturer with assembly service that can send me just one assembled board (and other bare or can throw them away) ? 
And when I mean cheap a mean really cheap like few 10s of $ not hundreds