Will a 3800 series II with supercharged option in a 2001 firebird go into a 2000 grand Prix gt. If extra parts are needed what is the cost?

Anything can be done if you have the time and the money. The supercharged engine will also need the 2 stage fuel pump, the computer to control it, and the heavy duty transmission. Not sure about the cooling system, but you may need a different rad as well. My advice, as always is, if you want a supercharged GP, buy one, don't try to make one. They are easy to find and relatively cheap and you get to start driving it the same day you buy it, not two years from now when you finally manage to finish the project car. Just sayin... Good luck.

Easier than put a V8. Don't even need to change the computer, just reflash it with HP Tuners. The most difficult will be to an U turn to the throttle body in the Intake Manifold, weld a little bit of aluminium in that Intake. More than that, just relocate fuel lines, A/C lines, well, the same things you do in any engine swap (conversion). It's nearly a direct swap. But remember, use the complete GTP engine, don't try to use GTP heads, supercharger and accessories in the Firebird/Camaro OEM. Make your homework, Google it, there's a lot of videos in Youtube about this swap. Easier to do in a 4th gen than in a Fiero... But I will prefer a 1999-2004 Land Rover 4.6 V8. It's the same Buick 3800 V6 that came in your car, with two more pistons and made in aluminium.