Imagine you're visiting your doctor.
You explain that you've had chest pains for a few days and are short of breath. Without looking at you he immediately starts to write out a prescription for antacid tablets. No examination. No questions. No interest.
How much confidence would you have in his diagnosis? Do you think you might be inclined to ask for a second opinion?
Now imagine that the second doctor asks a lot of questions about family history, current medication and general state of health. He then follows up with a thorough examination. Which doctor are you more inclined to want to use? If you were PAYING for a medical service, how much MORE would you pay doctor number two?
The first doctor's attitude is typical of many carpet cleaners. (maybe even MOST)
Instead of an inspection or home visit they prescribe the solution without knowing what the diagnosis is. Their view is that every carpet is the same and every cleaning process is more or less the same.
Here in the UK a doctor's service is free as part of the National Health Service but people always pay for carpet cleaning. And they will pay more, much more if they have confidence and trust in your service.
So rather than quoting a price over the phone or "winging it" upon arrival, act like a doctor if you want to get higher prices. Spend time asking many probing questions (even if you know the answers). Always diagnose the problem before giving a prescription for the solution.
I went to look at a job a few years ago. After asking several questions about the history of the carpet the lady impatiently said "Look... just give me a price will you?
She disqualified herself and I left immediately.