Thank you for the reply. I was actually only expecting an answer to 1 or 2 of them rather than all of them. 2 and 3 were more questions on the business side of (expenditure on staff finding exploits / expected number to find per year) rather than raw expenses and 4 was more a monetary return rather than a ROI, but thank you for all the answers nonetheless.

Just for clarification, am I correctly understanding your answer to 1b as the price of a zero-click iOS exploit being ~$4M in contrast to my stated $1-2M? If so, I will not openly contest that claim here and thank you for your time. Anybody reading to this point can substitute my earlier claims for $4M if so.