With this one I would charge a hourly rate of £50 for the job, I would also add 20% on as well.
Next I would not use a trolley if possible on all of the building, the main reason is you will be walking miles to kept filling up.
I would use microbore hose, which is a lot easier than garden hose to control.
At the moment, I have 140 metres of hose on a 100 psi pump, but at times I have also connected another 40 metres and still have the pressure to do the job.