Hey there, SGA. Just read your posts. I am new too, and had the very same questions. There is a lot that goes into drafting a proposal for a customer. I am still learning but here are a couple points to ponder. For me, depending on distance to the mission site, I could spend hours doing site surveys and plans for the required shots before even shooting the mission. If I can get clearance for flight through LAANC, thats quick and easy. When a customer needs images at a location where a Cert of Waiver from FAA is needed due to airspace restrictions, my company should earn a return on the extra time. Essentially, your Pt107 certificate is like a professional license for which you spent time and money to acquire so that you can fly commercially. Without that professional investment, you wouldn't have the credentials to make official requests of the FAA to operate in the NA lawfully.
My piloting skills are getting better now that I've officially documented a couple hundred hours in the air, but my post-processing skills continue to need improvement. I take online courses, some of which I pay for. I get through it fine on the software I'm using, but I spend way more time editing than I do flying. Post-capture processing is the biggest expenditure of my time, by far. Because I am still learning how to edit efficiently, I can't charge based on the time spent processing my images. If you have editing talent, you have the opportunity to optimize your fees by spending less time to deliver the finished product. Sending images to customers for review, making additional edits and submitting them for another review all takes time, especially if you have to send hardware back and forth. That's why I use DropBox- a quick, easy and inexpensive service to send files back and forth. If you haven't used it before, its easy, with plenty of tutorials online.
As my product improves, so will my fees. And the same will go for you. As you progress, find ways to improve your bottom line. Can you suggest that your customer send you the audio cuts they wish to use, or can you provide the customer a list of tracks for them to pick from? With that, you, the producer, can professionally insert their chosen soundtrack on your video production. Some customers may appreciate the additional service. Be sure the soundtrack can be used legally. I often use free soundtracks from sites like BenSound.com by simply giving attribution to the owner of the music as required, usually a short credit at the conclusion of the video, like "Music provided by BenSound. Com"
$800 isn't unreasonable. As you improve your craft and generate more business, you can increase your fee appropriately. That's what I'm hoping to do, anyway. This site has been very helpful and I appreciate the experienced pilots that give their time to help others. Some of the members here share some incredible images and video. I learn something just looking at what they share!
good luck SGA !!