What is a cast iron 2bbl intake worth

There were just 3 different super 6 manifolds that sold for right around $300 on eBay.

SUPER SIX 2 BARREL INTAKE MANIFOLD 4041043 Mopar Chrysler Dodge SLANT 6 225 2bbl | eBay

SUPER SIX 2 BARREL INTAKE MANIFOLD 4041043 Mopar Chrysler Dodge SLANT 6 225 2bbl | eBay

Slant 6 Super Six 2 Barrel Intake Manifold 4041043 Mopar CHRYSLER Dodge 225 2bbl for sale online | eBay