Along with everyone above .......... :iagree:
My pricing is all based upon an hourly rate that increases depending upon the size of the vehicle. Charges may/should increase depending upon the severity of the paint correction or neglect of the interior.
For each level of service you offer (or extras you add on) there should be some increase in price. Check out the pricing of other detail shops in your area that you would likely compete with and see what their price range is in comparison to yours. At the same time look to see if they're going to the same lengths with their detailing as you plan to with yours (level of work quality). Many times, as is the case here, detail services are little more than a wash & wax. Most likely you're catering to another level of customer who wants their vehicle "truly' detailed.
Take a look at my site & you'll find I've posted many of the "before & after" pics of past customer's vehicles (along with descriptions of the services applied to the vehicle), given definitions of my more involved services and listed all of my services in the most simplistic way I know.
So, what is your time worth?
What is the replacement cost of the chemicals you're using?
Do you have any overhead (gas, shop, electric, water)
How experienced are you?