keyboards are expensive, and the way Asus makes them nowadays, the keyboard alone is not replaceable. In older laptops, you could just pop out the whole keyboard.
Not so anymore with these new asus laptops. The keyboard itself is extremely difficult almost impossible to replace.
As shown below in the GL702, and like other GL laptops, the keyboards are welded to the palmrest deck by plastic rivets.
So if the keyboard breaks, they replace the whole deck.
This is potentially costly repair, as the parts are $80-$100. So you gotta treat the keyboard with care.
It's probably more cost effective to use a $5 usb keyboard most of the time.