Sounds kind a high
Did you call a marine/Yanmar place or an automotive place to get this quote. That sounds kind a steep for a one lunger head. Friend of mine just had one done on a 2QM and if I understood him correctly, thats more than his cost at an auto machine shop. An automotive machine shop does maybe 100 times more heads than a marine dealer. And are every bit as good, if not better and most certainly a lot cheaper.
Dream like you will live forever. Live like you will die tomorrow. ( James Dean )