That right there is the rational argument that doesn’t work if they’re not willing to part with those extra bucks and spend $3 on a cup of black coffee instead

That right there is the rational argument that doesn’t work if they’re not willing to part with those extra bucks and spend $3 on a cup of black coffee instead of $2. Customers do not always do what you think they will do. Besides, a lot of daytime customers are on fixed incomes.