What are older SBC, and SBF headers worth?

A buddy has been cleaning out some old parts out of his garage.

He has a set of Small block ford, and a set of Small block Chevy headers that have been hanging from his rafters for years now…

These headers are used but are in great shape.

How can I tell if these are worth anything?

He wanted me to put them on ebay, but I have no idea where to start with them. I’ll get some pictures up in a few days…

He says that they are at least 25-30 years old…

Depends on the brand and make. New SBF Tri-Ys go for @ $150.