I’d say it’s less about “time is money” and more about “I can afford 100 diapers with this week‘s pay check at 25 cents a diaper” and use my entire $25 budget if I go to Walmart, or “I can afford 25 diapers at 50 cents a piece and spend the remaining $12.50 on food - that will get me through this week” if I go to dollar general.

That’s literally the definition of living pay check to pay check - one’s outlook only cares about the next week or two, because you have to make trade offs between food, clothing, shelter, and essentials.