I was going to ask the same question about not affording to lose the customer.
I also wonder how you'll make more money by putting up the price and then paying someone else to do the job. You may lose the customer anyway when they don't see you turning up and being charged more for the privelidge.
They might offer your new employee the job and cut you out altogether.
Just as a side issue, we don't quote an hourly fee, we survey the job and then give a total price for the work. That way they aren't moaning because 'a neighbour saw you leaving 5 minutes early'. It also gets around the problem of you 'apparently' earning more per hour than they do
hope it helps
Les