If you spent $660 to install a BOV you overpaid. Unless I am assuming for yoru sake you have a $500 BOV and $160 into labor.$660 and it is pretty easy to install. Just getting your intercooler tube drilled for boost and welding the bung that the BOV sits on to the intercooler tube. Then some wiring. Pretty simple.
This helps release the pressure from the system when you let of the throttle really quick. It's so you don't hurt your turbos I believe