Here are some things to take into consideration...
You book your session for an hour and you think that is it. Done. What you're not thinking of is the traveling time to reach the location, sometimes set up time, time spent talking to the clients prior and post session, getting everything ready, the actual shoot, transferring and backing up the data, post processing (editing), reviewing, delivering the photos or scheduling a pick up. Each photo has its own process. It needs to be opened and converted weather it needs any enhancements or not. Each portrait gets at least 20 minutes from me. So if you get 10 edited images, that is at least 3 hours of work.
My gear is a full frame DSLR. The lenses I use are top of the line. Plus there are several to chose from for different needs. - it's the best. Lets not forget the most important gear... experience and education. I went to school for this. Its not just point and shoot. Its lighting, angles and posing.... so much more. And I still have more to learn! One big thing especially for larger jobs, is that sometimes an assistant is required. A second set of hands are always handy!
3. Online Services
Maintenance of a website is no easy task. You need to learn how to build one or pay someone to do it for you. Either way it still costs money for it to exist. A FaceBook account requires time to set up and time to maintain.
Apart from being a good photographer, they have to be CEO, marketing manager, CEO, salesperson, production worker, buyer, negotiator, driver, networker, organizer etc. That’s the kind of skill-set of Professional Photographer. Experience is the one thing that may beat everything. The Professionals are vastly experienced. They can advise you over a number of thing which you would not be able to decide. They know whats right and what could go wrong. What will work or not work. The professional will push themselves to get the best shot possible. You are choosing a photographer for their ability to take and create a beautiful photograph. This is not a forced photo such as you get at school. We take our time and skills to take the best photos possible. We are not pushing through a couple hundred children.
5. Insurance and Taxes
A legit business carries insurance. Yep thats not free either. We need to cover ourselves just in case just as you would your car or house. We also need to pay taxes. So we need to either pay for someone to do our taxes or in my case learn how to do it myself. I am learning as I go and making my own system. That takes time as well. So you see there is a great deal of time and care put into a photography business. You're getting someone who cares about their work and product.
The truth is that you get what you pay for. I gave out free sessions and the photos taken were that of a beginner photographer. As time and experience progresses so did the photographs and the pricing. You will get photographs worth the time and money involved.