It's the problem with anyone dealing with domains outside of their experience. It's really hard the first time through to even know the right questions to ask. And, sure, you can buy a pizza for a friend who has some experience with the domain and that helps to a degree. But, as you say, I'm not sure there's a good answer (other than just assuming it will cost 2x your estimate and 2x your time estimate).
The last part is only semi-kidding. Back when I was a project manager (where I DID have some domain experience), that was my rule of thumb and it was more accurate than I like to admit. In another former life in a different role, we had these 95% schedules which were really 95% confidence assuming nothing significant goes wrong schedules--which were about as accurate as you would imagine.
The last part is only semi-kidding. Back when I was a project manager (where I DID have some domain experience), that was my rule of thumb and it was more accurate than I like to admit. In another former life in a different role, we had these 95% schedules which were really 95% confidence assuming nothing significant goes wrong schedules--which were about as accurate as you would imagine.