£5 - and all this hassle? I'm not willy waving, but surely £5 is far too cheap unless it's like a single paned shop window or something of that ilk.
Let's help the guy price his jobs a little better than that; surely?
It's a confidence thing mixed with experience.
When I started window cleaning (trad) with a friend 13 years ago and before this forum began, some of our prices were so low that thinking back, it was ridiculous. We charged £1.50 for a council semi.
When you don't know the score and are new at the game, you can tend tend to give a price according to what you think the customer will accept which is usually way lower than what they are prepared to accept. I think it the fear of rejection or the customer saying 'no' but when each new job is a milestone, it's hard to be objective or confident about price.
After a few months, I can remember the first time I felt outrageous and quoted £5 for a 2 bedroom semi and the lady agreeing. I thought we'd hit the big time and it gave me a bit of a buzz and the confidence to ask for the same the next time.
My advice is the next time, the op should just say double the price he is thinking and see what happens. Some will say no, but some will say yes.