What is a cast iron 2bbl intake worth

Super six setups I say worth $250-350 if complete with all the brackets, kickdown. Last one I got came off a junker pickup for $75 but it was not in a boneyard.

Yup. That's what I've gotten for a few complete sets in the last 3 or 4 years.
Complete incl. kickdown, brackets, hardware, carb, cable.