well IMO, 500 is WAY too much for parts and labor on a fuel pump install. Also, I would run the wires inside my car too, but I do my own work, so I don't know the going rates on labor.
I also don't own a supercharger (yet
), so I can say that I wouldn't attempt that install myself without further research. As far as the pump, you can do that on a saturday by yourself without much hassle. If money is bothering you about the wiring, then just tell them to wire under the car and turn around and re run the wires inside the car yourself when you bring it home. That is also something I have done with mine, and it's not difficult at all. Probably takes about 20 minutes max.
Dave