CAI would be the cheapest mod for an actual gain. 325.00 for about 12 HP.

ECU Tune is a great mod, but slightly more at 500.00. Gains are about 22 HP.

Sprint Booster retails for 315.00 and is a noticable difference, but no power gain.

Exhaust will change sound and look, but very little performance gain and about 500.00

Injectors are needed to optimize an ECU tune and Intake.