A provocative post from Christopher Snowdon's Substack on whether the World Health Organization's list of "best buy" policies on alcohol - taxation, advertising restrictions, and availability constraints - pass the cost-effectiveness standard they set for themselves: averting the loss of a Disability-Adjusted Life Year for less than $100 in a low or lower-middle-income country and less than $500 in a rich country.
As a member of a free market think tank, the author likely opposes these policies on grounds other than cost-effectiveness, but he does a good job of steelmanning the case for them while providing substantial evidence for his conclusion that the answer is a fairly straightforward "no":
If reducing alcohol consumption (and, it is therefore assumed, alcohol-related harm) is the goal, the ‘best buys’ are neither a sufficient nor a necessary way to do it. Even advocates of such interventions admit that “reducing price and increasing availability does not always increase alcohol consumption and harm. Effects are dampened in affluent societies, and other factors may intervene”.
Worth a read for anyone interested in alcohol policy or the regulation of and reduction of harm from psychoactive substances more generally.
I expect there is some variability, the author in this piece focuses on alcohol, which I don't know that much about, but for "Reduce unhealthy diet" (Objective 3, page 10), CEARCH did a report here, which relates to WHO's best buys (if not quite exactly matching their specified intervention), and found it to be "49,419 DALYs per USD 100,000"
For best buys in education, I recommend Rachel Glennester's 80,000 hours podcast episode, where she praises the best buys, but also criticises how education spending is done
She has a second episode, which also touches on best buys
P.S. I'm not sure why this post has two disagree votes - seems like a perfectly valid forum post to me