editing pricing...

[Deb50]

HELP ANYONE!! i can't seem to get into anywhere when editing my listing that will allow me to explain to guests who need the sofa bed made up, that it costs an extra 20.00 a night regrdless of whether 1 or 2 people use the double bed in the main bedroom!!

all i need to be able to add is that "use of the sofa bed incurs an  extra charge of 20.00 per night..

thanks in advance to all...