... for a Help button, we already have a standard location for it. If it's not there, the space it would occupy is dead space. So it's essentially a zero-cost addition to the interface.
I disagree - filling up whitespace (or "greyspace" in this case) is no a zero-cost addition. You are adding to the visual complexity of the window. If the button should be there, make room for it - if not, leave the space empty. But don't put it there simply because there is room. Steven Garrity