If it were culturally accepted that search is something you need to pay for then yes, I am extremely confident it would come to cost very, very little per user. A startup with a small user base may well grow the way you say, but in a mature industry providing a commodity service to most of the population, margins will be squeezed razor thin and the prices will reflect the actual cost to provide.

Note that I'm not saying this is what will happen. I replied to a comment that was more about how we should want things to turn out. I'm saying we shouldn't denounce customer-paid startups for charging what they need to succeed in traditionally ad-funded industries, even if that means they start out as premium services for those willing and able to pay. Rather, we should cheer them on and advocate for the benefits their funding model brings, in the hope that they will succeed, grow, become commoditised and benefit everyone for pennies.

The alternative is to stick with the ad-driven, dross-filled panopticon we already have.