“Plus, you have to take into account the amount of ICs the US and/or UK has to spend to counter this extra battleship. The Battleship ends up paying for itself.”
I’m not sure I agree with you on that one. I find that the german navy often goes from being a threat (and therefore cost/effective) to being outnumbered and outcornered in just a few rounds. In that sense german battleship build round one is quite expensive and quickly becomes of no value.
In my games (unless UK and US went KJF-kamikaze) the german navy will typically flee into the mediterranean in round two. And if you spend too much ipc to avoid this, you’ll maybe conquer Africa - but on the expense of Eastern Europe, Norway and eventually Berlin…?