I would say £140 but that includes the gutter outside and glass doors as you will have to clean them anyway if using any chems. Around £5 per panel plus an extra £40 for the guttering and glass plus it being slightly difficult access to the back towards the wall (the finiels will be a bit more awkward that side) .
About hour and a half at a nice steady pace including set up and pack away.
that would be with cold water or half that time because of using hot water
or if your NWH you do it for free if you already clean the windows