Engineering costs have to be factored in.
Fabrication of dies to stamp out metal parts have to be factored in.
Fabrication of jigs to bend, align, and weld tubes have to be factored in.
Rubber parts and clamps costs have to be factored in.
Cost to produce printed instructions or videos have to be factored in.
Cost of packaging has to be factored in.
Cost of warehouse storage has to be factored in.
Cost of shipping has to be factored in.
Cost of procuring a test vehicle has to be factored in.
Cost of testing has to be factored in.
Cost for insurance has to be factored in.
Cost for employees has to be factored in.
Profit margin has to be factored in - they're not going to make these for free!
I seriously doubt any of us could make an intake that looks like it was made for the car for less than $400.00!
2.0
AEM Cold Air Intake Install on 2019 Forte - YouTube
1.6T
AEM Cold Air install on SPACE GHOST 2020 KIA Forte GT - YouTube