Yep....that's probably the price for a correctly ported head by someone like Nik, Karl, Mountune etc.

But then you need the valves, springs, followers.....and of course a damned good head to start off with, as you wouldn't want to spend that sort of money, using a head that was on it's final skim

I'm thinking around 3k - 3.5k for an off the shelf Group A Head. (All fully built up, and complete with valves, springs, followers etc and ready to fit.)