I would disagree, 5 men averaging 30k per person per year, thats very good going, and I would think some damnn good prices too.
The logistics of running a business with 5 workers is high, particularly one so labour intensive as window cleaning.
Most of us are one man outfits, a team of 5 is big (relative).
How many window cleaners do you know who are VAT registered?
If it was your business, and you had 5 working for you, what would you be paying them? Probably less than 15k per year per person, and if you were one of that 5 then your income would be higher again.
I know there are going to be things such as Employers liability, Employers NI and many other overheads to consider, but if the business is the real thing, it would certainly give a good return at the end of the day.
Mind how you go,
Ian