i charge at least £20 for an easy one, and about £50 for a large dirty one,
Are we still talking conservatories here 
as i was writing it i was thinking ooh er!

thought i would share my story as im on here, a man from saudi arabia asked me to clean his windows, over the phone i said i charge at least £20 - (saves wasting my time when i turn up and they expect it done for a fiver) he said cant you give me a discount, do it for £15, no i said. anyway i turn up and didnt realise he had a con, and they hadnt been cleaned for at least 5 yrs! then he said insides need doing too! they were just as bad!. i said im really sorry but its going to be £90, he managed to batter me down to £80, but in the middle of it he said can you clean my walls and wood floor in the con (damp spores) yeah i said if you pay extra. he said no can you do it for free, i just looked at him stupid! some people! anyways 2 of us took 2hrs to clean the house so it didnt work out so bad. wont let anyone else batter me down next time! im too soft! he did offer us a cuppa at the end, so not so bad a guy, and he want the windows done every 4 months for £30