There are so many factors that go into pricing photography and it's completely unique to the individual. These costs include living expenses, equipment, experience, post-processing, software, insurance, the list goes on and on. To my delight, I came across this video today on AdoramaTV. It's hosted by Mark Wallace of Snapfactory.
He really delves into how to actually calculate your costs and get your numbers together so when the question comes up, you're not just pulling numbers out of the air. This is exactly what I wanted to find. I have a lot of homework to do to get my numbers together, but I at least have a direction for what I should be looking at.
Have a look!