I think the article is less making a comment on “how many hours of time you need to put into reading before it’s worth the monetary cost you laid down for it”.

I think the article is less making a comment on “how many hours of time you need to put into reading before it’s worth the monetary cost you laid down for it”. I think it’s trying to remind people that before you get the utility you wanted out of a (non-decorative) book, you need to pay not just ($14.99), but ($14.99 + 10 hours), or indeed ($14.99 + 1 hour). I understood the article to encourage more thoughtful budgeting of that second kind of cost, and that we are tuned to automatically mostly consider the first kind of cost.