My initial 146whp & 156wtq setup cost just over $800, using all junkyard/salvage yard parts. The turbo cost $100, intercooler cost $25, since that's where the main dollars are spent, the rest is just piping and metal. You must be a great welder or know one who will do the work for nothing or next to nothing.
A BOV isn't needed, but a bypass valve is. You can get a cheap plastic bosch bypass valve for around $35 new. Even with mild boost, at a minimum, a bypass valve is a good idea.
When it comes to fuel, here's a cheap fuel solution that I think would work for up to 150 whp. Buy a standard hobbs pressure switch, that clicks on at 4 psi. Hook the switch to a vacuum hose in the intake manifold. Hook one end to a ground, and hook the other ends to each of the grounds on the fuel injectors. That way when the intake manifold reads 4psi or greater, the switch clicks on and grounds the injectors 100%. That should give you enough fuel for at most 150whp at 4-5psi, and is basically what the Jackson Racing Supercharger black box is. That would cost you around $30. More than 150whp and 5psi is when the big bucks start rolling in, or rather out.