Depends on where you live
Although I don't drive to work, a friend who lives on HK Island told me once that there was a special deal for airport staff at the HK AEL station, and I would assume probably at the other 2 AEL stations as well. I seem to remember that there is a monthly rate option, so that you could pretty much use it as your permanent car space.
Sorry I don't know prices or other details.