Seperately, the JWT exhaust is around $950 shipped from Phuong (GR Racing), Pop is $105 shipped from Coz, and ECU is $575 from Coz, so the 396 kit will save you a couple hundred bucks. The JWT exhaust is very good but not loud. You can get less expensive SS exhausts and Ash ECU is half the price.
Do some research so you can make the right decision for you.