So who do you use for search? The most mentioned around here is Duck Duck Go but they derive their income from ads also.

I mostly use Google

"if you find it acceptable to watch ads (I don't), use it"

"I mostly use Google"

Are you trolling?

no, I am not

How much would you be willing to pay for search as a premium service?

I'd pay 5-10 bucks a month without a second thought. That'd amount to something like 420-840 bucks to DDG since I've roughly started using it (somewhere around Snowden leaks).

It's not a larger amount than they would earn from me if I didn't use an ad-blocker, but it's 100% larger than they've earned from me over the years.

Depends on what? Let's assume we're talking Bing-level quality and DDG-level privacy. How much would you pay per month?

a lot of factors - future potential - features/technology behind it - feelings - financial situation - alternatives - need for a search engine

I don't even know if I'd pay anything at all.