Mike, I am not talking about the whole house, or complete conservatory clean, just the conservatory windows.
I have one conservatory that takes me about 5 minutes. I have another that takes me about double that and they are priced on the £2 - £5 basis. It works out quite well for me.
BTW, I am not talking about conservatories that would look at home in Kew Gardens, just your average conservatory on your modern house.