Touring Caravan clean

Hello Folks

On eof my customers has asked me how much it would cost to clean the outside of her medium size caravan. I think it is made out of aluminium. I had a look at the roof which was a little green in places but on the whole the caravan wasnt too bad. I was thinking to quote between 30 and 60 pounds.

Have any of you out there ever cleaned a caravan. If so I would be interested to know how much you charged? and how you went about cleaning it?

Depending on size £30 we have done a few , I used to do my own with the pole when I had it .