A certain hotel next to LHR requires you to be a guest at the hotel (i.e. the pilot has to pay a standard room rate of a good £80+)
Another one in Cheshire charges upwards of £100 on occasions.
They say the charge is to offset the annoyance factor to the guests and maybe to have staff standing by, but I've never seen staff looking out for the machine and guests tend to be impressed with a chopper using the hotel, rather than annoyed.