This sounds similar to something like Rocketreach or Zoominfo. Those who are willing to pay will pay, but I think most people just browsing for emails. wouldn't. There's enough info online for folks to be savvy and find/guess (such as email address format) contact info without paying for it though. Exceptions would be companies with minimal/no web presence and individuals who stay offline (i.e. no LinkedIn).

Through searchfunder, we have access to data axle. I used it a couple of time and I found it very affordable. You can give it a shot and that will give you an idea about the price point that others are charging.