Turbo kit will be the most expensive, due to the fabrication costs. PowerFab is making them, but they are not massed produced. So They still have to be made by hand. They have made four so far. SIK X's, Toon714's, Clifford's, and now Redlantern's. They had a "small' hand in mine's.
TRD starting is the cheapest.
Then PowerFab, or (whichever performance shop you choose) will be the most expensive.