I know there are many variables added to an engine especially when you add a turbo. The basic kit would include all tubing, intercooler, turbo, manifolds, a tune, BOV, the basic stuff to just get your car started. If you wanted to increase the boost it would be safe to rebuild the motor with a lower compression and all forged internals. After those first two steps the majority of your money has been spent, then its just adding some fuel, upping the boost, and tuning the beast for more power.