Price On A Factory 318 Poly 4bbl. Intake Manifold?

Can any of you guys that are in the know, tell me what a factory, cast iron, 4bbl. intake manifold for a Carter AFB, are selling for in this modern day and age?
I have a lead on one, with an unknown number AFB on it.
Don't know if i should get it or not.
Haven't had one of these in decades.
Thank's in advance.