Similar to Dave's comments, its important to understand all the aspects of this type of project bid request since the prep time, drive time, flight time, post processing time, deliverable packaging (video, photos), and customer reporting all add up very quickly. I'd recommend setting several pricing/fee tiers for the different activities involved. Here is an example: Prep-time $30/hr, drive-time $30/hr, flight time $125/hr, post-processing $30/hr, packaging-reporting $30/hr. These $/hr amounts are totally arbituary. When you have a standard billing/pricing/fee rate, you can make exceptions