Joe will come out to meet you and provide a detailed written estimate -- one you could use over the phone to compare rates per window against a competitor. You would see that Joe's pricing is reasonable and average against the going rate. Naturally, it would not be plausible to completely assess pricing site unseen. It is a bad idea to list on a website prices per style window because of factors such as window size, height from the ground, landscaping challenges, and type of pane grid on each window.
Joe's prices are much less than competitors who advertise everywhere, especially those that mail expensive, pretty postcards to every house in their footprint. The cost to do so along with their office and payroll expenses force them to charge outrageous rates per window. On the other hand, Joe grows his business through referrals at no cost; and does his own admin and accounting. This enables Joe to price right. And, remember, Joe is there at every job every minute.
Conversely, beware of new comers to the trade and other "want-to-be" window cleaners that don't deliver the best results; and consequently are desperate for business. The first clue is that their prices are below the going rate, or they are offering a tempting "introductory offer." I recommend a face-to-face meeting with the guy that will actually be cleaning your windows to get the sense they are very experienced and accomplished -- with a large following, and ask for referrals in your neighborhood. Since a window cleaner will be in every room in your house, you want to know you can trust him 100%.
Window cleaning is different from other trades in that there is a very large disparity in quality, professionalism, and customer service. Check out my home page, my video, my bio, and info on my helper to find out why I am the window cleaner of choice.