I sanded mine but they were so badly chipped and I couldn't get them sanded back very smooth. So I hit them with a coat of spray putty then painted them.
I didn't clear coat them though. Wishing I would have now!
Its $50 per light. But they come up like new.
Not sure how long as he is using a new sealant which is supposed to be better. But he said it will last a lot longer than the stuff in the kits.
Had a mate who is a detailer come over and polish my headlights and then seal them. Sealant is supposedly harder and lasts a lot longer that the stuff in the kits you can buy.
They look awesome!