[EndlessAzure]

Up to you if you want to swap the whole headlight or just the ballast


The only ballasts that you should use for the factory headlights are factory ballasts.

• They are a box that's screwed onto the headlight. They're pretty expensive from the dealer (~$350 each) https://parts.subaru.com/a/Subaru_20...10-840-01.html
• You can find them used, separated from the headlight for cheaper (~$50-$100 each )

If you want replacement headlights, you could get used factory HID headlights (usually ~$400 for the pair).

Aftermarket headlights vary, but there rarely as good as OEM (both in terms of build quality and light output). Only HID headlights need and come with ballasts. LED have integrated boards or COBs, and Halogen lights don't need any extra electronics.