I tried Rtila but that is more a Swiss army knife for scraping, and it requires more preparation than I have time to figure out. Reoon is really good at scraping Yellow Pages. It is easy to get potentially hundreds of thousands of leads (depending on what you are looking for of course), and in my case it finds email addresses of 1 in 8 scraped profiles.
The interface of the software product (for Windows and Mac) is pretty horrible, but it works. It looks and feels like Windows 3.1.
Some things could have easily been automated (e.g. it wants you to upload a partial list of cities that it supplies - the whole purpose of buying software is to solve that kind of issues).
Anyway, for the price per lead this tool is hard to beat. Not sure how accurate/fresh Yellow Pages are, but it is clear the sheer number of leads in Yellow Pages beats any other source (including Apollo, LinkedIn) hands down. (Promised 25k email verification credits by the seller for an unbiased review, technically making this an advertisement.)