You need three things.
One of them come with a turbo kit.
Performance Chip
Cold Air Intake-In turbo Kit
Exhaust System-Not just muffler.
Or you can buy a Turbokit without the turbo to add 50HP. This should cost around $800. Same as buying the Chip, Intake, and Exhaust.
When you can afford the Turbo, you can just add it on. Single Turbochargers cost at least $1700. You need a turbokit to make it work.
Either way, it will cost you more than $800 to add 50HP.