This link might help some:
What do you Charge for Drone Service
Good afternoon Marlene. With all due respect, you're getting your cart WAY ahead of your horse on this one. You need to have all of your ducks in a row and have them well trained before offering anything at all. It's better to start slow and show your professionalism than to jump the gun and look unprofessional. Just my opinion there.
What is your skill/experience level and what kind of finished product do you offer?
How long does it take for you to shoot an average Real Estate shoot? How much time do you spend traveling to & from the jobsite?
How much time do you spend on average in Post Production for each project?
How much does it "COST" you to operate your business each month?
How much do you need to make per hour to stay in business?
How much would it cost you to replace your equipment should you have a failure and have to replace the complete aircraft today?
Those questions will "help" you to know how much to charge. To make it even more complex it really depends on what your local competition saturation is as well as what the local market will support.
You need a detailed and comprehensive Business Plan to help guide you for start-up and the first 3-5 years of running a new business.