If you don't regulate them you don't pay directly but pay in medical cost for conditions such as asthma. You also get lower children IQ which is worth something. According to the EPA calculations the children IQ is worth more than the increased monetary cost of coal plants due to mercury regulation.
As per a recent comment this thread is meant to voice contrarian opinions, that is anything this community tends not to agree with. Thus I ask you to post your contrarian views and upvote anything you do not agree with based on personal beliefs. Spam and trolling still needs to be downvoted.