There's a standard way of looking at this, and in the US the answer is yes, the life of everyone is worth the same, and that's how other economic decisions are made in the US (e.g. safety regulations need to meet this same standard). Suddenly changing the way you value lives to suit a particular outcome for a particular decision doesn't seem right. If you are going to look into the economics you should consider not only deaths but costs of all other hospitalizations, long term effects and various other second order effects. (check out the recent Planet Money episode about the value of lives in the US and their discussion of whether or not the US should lock down, tl;dr economically yes by orders of magnitude).
Stuff like highway safety is done with a single cost per human life saved. That's fine there, since the cause of death isn't terribly sensitive to age (and to the extent that it is, there are effects in both directions--young people drive more and more dangerously, but are more likely to survive a given accident, so it partially nets out).
But like many diseases, the coronavirus is far more sensitive--the IFR for a 75-year-old is >100x that of a 25-year-old[1]. That's the reason why health care spending is near-universally assessed by cost per quality-adjusted life-year (QALY) saved. To do otherwise would yield absurd results, paying the same to restore a dying child to perfect health as to extend a centenarian's life by another month of agony. Around the usual ~$100k per QALY saved and counting both the deaths and loss of quality in severe but non-fatal cases, I believe that masks, social distancing, remote working where possible, and closure of the highest-risk businesses (theaters, nightclubs, etc.) until a vaccine is available are likely cost-effective, but facility closures beyond that are not (except to any extent required to stop the medical system from getting overrun).
