400BB Heads Question

First off, I want to thank a lot of you for answering all of my noob questions without making feel dumb, I do that enough myself... LOL

My question is simple enough I guess. My heads do need a valve job at the least. At what point should I look at getting new heads? These are 452 Iron Heads for a 400 Big Block btw.

What does a normal head rebuild cost?

Questions like that.

Thoughts?

View attachment 499724
Author: badvs3vil