Quoting a job should not be that hard. You have equipment costs that need to be amortized, you have hourly rates to pay for both flying and editing, and you have to cover monthly expenses. The calculator below is by no means a complete tool to use for every job you encounter. However, it should give you a fairly accurate place to start from to at least cover your basic costs.
Clever idea. Not sure how they monetize it but it certainly qualifies as a public service.