A C4 Chevrolet Corvette turbo kit will average between $6,000 and $8,000. But, of course, the price of the kit will depend on what kind you get, where you purchase it from, and any added labor costs to have it installed.
You can always shop around for different turbo kits to find some that are more affordable. You can also get estimates from other mechanics for kit installation to save a little money on labor costs.