That's not how you do a cost/benefit analysis. You can't do "what would have happened if the red third of the country had listened to my preaching and repented". You have to analyze a policy. To do a proper analysis you need to know the hypothetical policy (instead what you do is you pull out an unsupported number like 200K out of your ass). What's even more funny if you have cost/benefit entirely reversed (the benefit of the policy is lives saved...the cost is the cost of the policy).
Shall we rehash masks on kids? Benefit: small....cloth masks are apparently "facial decorations", Kn95s for them are in large part counterfeit and surgicals aren't properly fitted, they are at incredibly small risk, they seem to transmit less. Cost: torturing at risk kids (deaf, toddlers, ADHD, autism), depression and mental illness scars, environmental, speech and learning delays, incidents with people thrown off flight and other confrontations, societal relationships.