Dell charging to change the default boot device

On Dell’s online system configurator, in the midst of questions like ‘do you want Office?’, ‘do you want a 20″ widescreen monitor?’ etc., is this:

Dell boot device

This is just a bios option that takes half a second to change, but I don’t really object to Dell charging as it’s not something many people know about. However, I’m pretty sure any computer will boot to the hard drive by default – what does the first £3 actually buy you?