What are the LD4B manifold worth?

I'm looking at a LD4B manifold for my 1967 Dart with a 273. The guy wants $300 for it. That seems high. He says its a hard to find manifold. What is the price range they go for?
Look, the simplest thing to do is search, use the search bar in the upper right & type in "LD4B" & hit enter. Many have been listed & sold on this site, read what's there. Keep in
mind, exceptionally clean examples are going to demand more $$$, but a rough/slightly corroded or damaged unit will run just as well as long as it's functional.