The new issue of YNOT Magazine is about Age Verification:
https://www.ynot.com/ynot-magazine-2018-04/
There are several times when age verification pricing comes up, but there are just general comments about it. In the articles I read, they didn't pressure the people they are talking to into sharing any actual numbers. If you are running a business, numbers are what you need to understand the issue.
Anyone with direct knowledge of what the pricing looks like for the major Age Verification services?