I priced a new one today, didnt count the windows as such to work it out accordingly, but looked around the property, figured the outhouse was actually quite a simple one to do (fairly large panes, 3' x 3') and thought 30 minutes... I put in £14.00.
That to me works out at the rate I'm happy with per hour, but am I prepared to 'risk' the rejection if the customer thinks the price is steep?
She puffed a bit at the price, exclaiming her previous window-cleaner ha been cheaper !!! Oh arr I says

She was happy enough once Id explained the reasoning of the price and she was a very happy customer as I left the property 30 minutes later.
I think pricing is about respect, self-respect that is.
Are you worth the hourly rate you want or is reasonable; considering all things; weather, unpaid sickness, unpaid holiday, unpaid bank holiday, travel costs, equipment costs, materials. To me I might earn £30.00 an hour CLEANING, but do I take that home....NO WAY!!!!
Pricing can be difficult, but I always think its best to stop and hide round the corner from the customer, count to 10 and be sure youre confident about the figure youre about to suggest.
Matt