Two things have to be considered here, price of job and how long it takes to complete. As an example, I was in the USA a few years ago and went out with a window cleaner for the day; we stopped in a shopping mall because he had a shop to price. For a bit of fun we decided to price the job separately then tell each other what price we had come up with. He priced it at exactly double what I priced, and estimated the job would take exactly double the time I had estimated. Result was both of us would be working for the same amount of money per hour, both of us would leave the windows at the same standard of cleanliness. I would be working faster than him wasting more energy, but I would have more chance of getting the job with my price.
What is best, I dont know, depends on your area and who works in it.
Peter