Would a grand prix GTP be unusualy expensive to insure?

It depends on the year and stuff, too. For example, I have a 95 GTP. They weren't supercharged back then, but it still made 210hp and 210ftlbs. I pay about $500 every six months as I'm under 21. If you want to have lower insurance rates and have a supercharged one get a 97 or 98. 98 was the last year that "GTP" was a package for a GT and not a trim level. My 95 shows up on insurance as a "1995 Grand Prix 2dr SE" as GTP was just a package you get from the factory. Also, the grand am's would be cheaper. If you want your insurance even lower, don't be listed as the primary driver of the car. If your family has an old car (like an old Taurus or something) be the primary on that. Having above a 3.0 (you have to prove it) generally gets you a little break on it, too.